Method for manufacturing resist composition purified product, resist pattern formation method, and resist composition purified product

Abstract

To provide a method for manufacturing a resist composition purified product in which impurities are further reduced and can reduce occurrence of defects when a resist film is formed.SOLUTION: A method for manufacturing a resist composition purified product includes a step of filtering a resist composition through a filter having such a porous structure that adjacent spherical cells are communicated with each other. The filter includes a porous film containing at least one kind of a resin selected from the group consisting of polyimide and polyamide imide. The resist composition contains a resin component (A1) whose solubility to a developer is varied by action of an acid, and an organic solvent component. The resin component (A1) contains a copolymer having a constitutional unit (a01) having an onium salt structure to produce a sulfonic acid by exposure, and a constitutional unit (a02) having an onium salt structure to produce a carboxylic acid by exposure.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a purified resist composition product, a method for forming a resist pattern, and a purified resist composition product. [Background technology]

[0002] In the lithography technique, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and then a development process is carried out to form a resist pattern of a predetermined shape in the resist film. In recent years, advances in lithography technology have led to rapid progress in miniaturizing patterns in the manufacture of semiconductor elements and liquid crystal display elements. A common method of miniaturizing patterns is to shorten the wavelength (higher energy) of the exposure light source. Specifically, ultraviolet rays such as g-line and i-line were used in the past, but currently, KrF excimer lasers and ArF excimer lasers are used in the mass production of semiconductor elements, and development is also underway using EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energy) than these excimer lasers.

[0003] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources, resolution capable of reproducing patterns with fine dimensions, etc. As a resist material that satisfies such requirements, a chemically amplified resist composition that contains a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure, has been used so far. In the chemically amplified resist composition, a resin having a plurality of structural units is used as the base component. Known examples of the acid generator component include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0004] However, as patterns become finer, the influence of impurities present in resist materials becomes more apparent in pattern formation. In response to this, in the manufacture of resist compositions, the composition is generally purified by passing it through a filter to remove impurities therein (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7195418 Summary of the Invention [Problem to be solved by the invention]

[0006] Lithography technology is further advanced and the application field is expanded, and patterns are rapidly becoming finer. Accordingly, when manufacturing semiconductor elements, etc., a technology capable of forming a pattern with fine dimensions in a good shape is required. Therefore, resist materials are required to have higher sensitivity and improved lithography properties. In response to this demand, a study is being conducted on the use of a resin that has a structural unit that generates acid upon exposure as a base component of a chemically amplified resist composition. On the other hand, when forming a resist pattern with a size of several tens of nanometers, the problem of defects occurring during resist film formation becomes a significant problem.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for producing a purified resist composition product, which further reduces impurities and is capable of reducing the occurrence of defects during resist film formation, a purified resist composition product produced by the production method, and a method for forming a resist pattern using the purified resist composition product. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration.

[0009] A first aspect of the present invention is a method for producing a purified resist composition, the method comprising: a step (i) of filtering a resist composition through a filter having a porous structure in which adjacent spherical cells are connected to each other; the filter has a porous film containing at least one resin selected from the group consisting of polyimides and polyamideimides; the resist composition contains a resin component whose solubility in a developer changes due to the action of an acid and an organic solvent component; and the resin component comprises a copolymer having a structural unit (a01) having an onium salt structure that generates a sulfonic acid upon exposure, and a structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure.

[0010] A second aspect of the present invention is a method of forming a resist pattern, comprising: a step of obtaining a purified resist composition by the method for producing a purified resist composition according to the first aspect; a step of forming a resist film on a support using the purified resist composition; a step of exposing the resist film; and a step of developing the exposed resist film to form a resist pattern.

[0011] A third aspect of the present invention is a purified resist composition product containing a resin component whose solubility in a developer changes due to the action of an acid and an organic solvent component, wherein the resin component includes a copolymer having a structural unit (a01) having an onium salt structure that generates sulfonic acid upon exposure and a structural unit (a02) having an onium salt structure that generates carboxylic acid upon exposure, and wherein the number of counted particles having a size of 0.135 μm or more, as counted by a light scattering type liquid-borne particle counter, is 0.1 particles / mL or less.

[0012] A fourth aspect of the present invention is a method of forming a resist pattern, comprising the steps of forming a resist film on a support using the purified resist composition according to the third aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. Effect of the Invention

[0013] EFFECTS OF THE PRESENT DISCLOSURE The present invention is capable of providing a method for producing a purified resist composition product, which further reduces impurities and is capable of reducing the occurrence of defects during resist film formation, a purified resist composition product produced by the production method, and a method for forming a resist pattern using the purified resist composition product. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic diagram showing one embodiment of communicating holes constituting a polyimide-based resin porous membrane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this specification and claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The term "halogenated alkyl group" refers to an alkyl group in which some or all of the hydrogen atoms have been substituted with halogen atoms, and examples of the halogen atoms include fluorine, chlorine, bromine and iodine atoms. The term "fluorinated alkyl group" or "fluorinated alkylene group" refers to an alkyl group or alkylene group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrases "may have a substituent" or "may have a substituent" include both cases where a hydrogen atom (-H) is replaced with a monovalent group and cases where a methylene group (-CH-) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

[0016] The term "polyimide resin" refers to either or both of polyimide and polyamideimide. Each of the polyimide and polyamideimide may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and an -NH- bond. A porous film containing at least one of polyimide and polyamideimide is sometimes called a "polyimide-based resin porous film." A porous film containing polyimide is sometimes called a "polyimide porous film." A porous film containing polyamideimide is sometimes called a "polyamideimide porous film."

[0017] The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0018] The term "acid dissociable group" refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group. The acid dissociable group constituting the acid decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0019] The "base material component" is an organic compound having a film-forming ability. Organic compounds used as base material components are broadly classified into non-polymers and polymers. As non-polymers, those having a molecular weight of 500 or more and less than 4000 are usually used (hereinafter referred to as "low molecular weight compounds"). Hereinafter, when "resin", "polymeric compound" or "polymer" is mentioned, it refers to a polymer having a molecular weight of 1000 or more. As the molecular weight of a polymer, the weight average molecular weight calculated in terms of polystyrene by GPC (gel permeation chromatography) is used.

[0020] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. αx ) is an atom or group other than a hydrogen atom. αx Itaconic acid diesters in which the substituent (R αx It also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group of the acrylic ester. Unless otherwise specified, the carbon atom at the α-position of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent will sometimes be referred to as an α-substituted acrylic ester.

[0021] The term "derivative" refers to a concept that includes compounds in which the hydrogen atom at the α-position of the target compound is replaced with other substituents such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of the hydroxyl group of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is replaced with an organic group; compounds in which the hydrogen atom at the α-position of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is bonded with a substituent other than a hydroxyl group, and the like. The α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. The substituent that replaces the hydrogen atom at the α-position of hydroxystyrene is R αx Examples of the alkyl group include an alkyl group and a halogenated alkyl group.

[0022] In the present specification and claims, some structures represented by chemical formulas may have asymmetric carbons, and may have enantiomers or diastereomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture.

[0023] (Method of manufacturing purified resist composition product) The method for producing a purified resist composition according to the first aspect of the present invention includes a step of filtering the resist composition through a filter having a porous structure in which adjacent spherical cells are connected to each other (hereinafter, this step is also referred to as “step (i)”). The filter has a porous film containing at least one resin selected from the group consisting of polyimide and polyamideimide. The resist composition contains a resin component whose solubility in a developer changes under the action of an acid and an organic solvent component. The resin component contains a copolymer having a structural unit (a01) having an onium salt structure that generates a sulfonic acid upon exposure and a structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure.

[0024] In step (i), impurities such as particles are removed from the resist composition, yielding a purified resist composition product with high purity. According to the production method of the first aspect, in particular, a filter is used that has a porous structure in which adjacent spherical cells are connected to each other and that is equipped with a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamideimide, so that highly polar components and polymers that have been difficult to remove in the past are sufficiently removed from the resist composition, and in particular highly polar polymers are specifically removed. By containing a copolymer having the structural unit (a01) and the structural unit (a02) in the resist composition that is the object to be filtered, more highly polar components can coexist as impurities. In addition, in step (i), metal components are also sufficiently removed from the resist composition as impurities. These metal components may be originally contained in the components constituting the resist composition, but may also be mixed in from the resist composition transfer route such as piping and joints of the manufacturing equipment, etc. In step (i), for example, iron, nickel, zinc, chromium, etc., which are likely to be mixed in from the manufacturing equipment, etc., can be effectively removed.

[0025] <Process (i)> Step (i) is a step of filtering the resist composition through a filter having a porous structure in which adjacent spherical cells are connected to each other.

[0026] Filter The filter used in this step has a porous structure in which adjacent spherical cells are connected to each other. For example, such a filter may be made of a single porous membrane in which adjacent spherical cells communicate with each other, or may be made of the porous membrane together with other filter media. Other filter media include, for example, nylon membrane, polytetrafluoroethylene membrane, tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA) membrane, or membranes modified from these.

[0027] In this filter, the area of ​​the porous membrane before and after passing the liquid is preferably sealed so that the resist composition supply liquid and the filtrate are not mixed and are separated.This sealing method can be, for example, a method of processing the porous membrane by bonding with light (UV) curing or heat (including bonding by anchor effect (thermal welding, etc.)) or bonding with adhesive, or a method of processing the porous membrane by bonding with other filter material by an incorporation method, etc.As this filter, it can also be mentioned that the porous membrane as described above is provided in an outer container made of thermoplastic resin (polyethylene, polypropylene, PFA, polyethersulfone (PES), polyimide, polyamideimide, etc.). In such a filter, the shape of the porous membrane may be flat or tubular with opposing sides of the porous membrane joined together. The surface of the tubular porous membrane is preferably pleated, since this increases the area of ​​contact with the feed liquid.

[0028] About the "porous membrane with adjacent spherical cells connected to each other" The "porous membrane in which adjacent spherical cells are in communication with each other" of this filter has communicating holes that connect adjacent spherical cells to each other. The communicating pores are formed by individual holes (cells) that impart porosity to the porous membrane. Such pores include pores whose inner surfaces are almost entirely curved, and may also include pores of other shapes.

[0029] In this specification, such holes whose inner surface is almost entirely curved are referred to as "spherical cells" or "approximately spherical holes." In the case of spherical cells (approximately spherical holes), the inner surface of the hole forms an approximately spherical space. Spherical cells are easily formed when the microparticles used in the manufacturing method for a polyimide-based resin porous membrane described below are approximately spherical. The term "approximately spherical" includes a perfect sphere, but is not limited to a perfect sphere, and includes a substantially spherical shape. "Substantially spherical" means that the sphericity, defined as the major axis / minor axis, expressed as the major axis of the particle divided by the minor axis, is within 1±0.3. The spherical cells herein preferably have a sphericity of 1±0.1, more preferably 1±0.05. In a porous film in which adjacent spherical cells are in communication with each other, at least some of the communicating pores are formed between the adjacent spherical cells.

[0030] FIG. 1 shows a schematic diagram of one embodiment of the communicating holes that form the porous membrane. In the porous membrane of this embodiment, the inner surfaces of the spherical cells 1a and the spherical cells 1b are almost entirely curved, forming a substantially spherical space. The spherical cells 1a and 1b are adjacent to each other, and a communication hole 5 is formed through the overlapping portion Q of the adjacent spherical cells 1a and 1b. The material to be filtered flows through the communication hole 5, for example, in the direction from the spherical cell 1a to the spherical cell 1b (in the direction of the arrow).

[0031] In this manner, in a porous membrane having a structure in which adjacent spherical cells are interconnected, it is preferable that a plurality of pores (spherical cells, interconnected pores) are connected to form a flow path for the material to be filtered as a whole. The "flow path" is usually formed by interconnecting individual "holes" and / or "communicating holes". The individual holes are formed, for example, in a later step of a method for producing a polyimide-based resin porous membrane described below, by removing individual particles present in a polyimide-based resin-particle composite membrane. The communicating holes are adjacent holes formed in a later step of a method for producing a polyimide-based resin porous membrane described below, at a portion where individual particles present in a polyimide-based resin-particle composite membrane were in contact with each other, by removing the particles in a later step. In the porous membrane, spherical cells and holes that connect adjacent spherical cells are formed, and the degree of porosity is increased. In addition, in the porous membrane, the spherical cells or the holes are open on the surface of the porous membrane, and the holes that open on one surface communicate with the inside of the porous membrane and open on the other (back) surface, forming a flow path through which a fluid can pass through the inside of the porous membrane. And, according to the porous membrane, the object to be filtered flows through the flow path, and foreign matter contained in the object to be filtered is removed from the object to be filtered before filtration.

[0032] The porous membrane has a flow path inside, which is a series of communicating holes formed by spherical cells with curved inner surfaces, and the surface area of ​​the inner surface of the spherical cells is large. This allows the object to pass through the inside of the porous membrane, and when the object passes through while contacting the curved surfaces of the individual spherical cells, the frequency of contact with the inner surface of the spherical cells increases, so that foreign matter present in the object to be filtered is adsorbed by the inner surface of the spherical cells, making it easier to remove the foreign matter from the object to be filtered.

[0033] The porous membrane preferably has a structure in which spherical cells having an average pore size of 10 to 2500 nm are interconnected. The average pore size of the spherical cells is preferably 10 to 2500 nm, more preferably 20 to 1000 nm, further preferably 30 to 500 nm, and particularly preferably 40 to 400 nm.

[0034] The flow path inside the "porous membrane in which adjacent spherical cells are connected" may have, in addition to the spherical cells and the connecting holes between the spherical cells, holes of other shapes or connecting holes including these. The spherical cells may further have recesses on their inner surfaces. The recesses may have holes that open to the inner surfaces of the spherical cells and have a smaller diameter than the spherical cells.

[0035] Examples of "porous membranes in which adjacent spherical cells are connected" include those containing a resin, and may consist essentially of only resin, with preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 99% by mass or more of the entire porous membrane being resin.

[0036] The porous membrane contains a polyimide resin. A porous membrane containing a polyimide resin is excellent in terms of foreign matter removal ability, strength, and stability of lithography properties before and after filtration. The porous film contains at least one of polyimide and polyamideimide as a resin, and preferably contains at least polyimide. The porous film may contain only polyimide as a resin, or may contain only polyamideimide, but preferably contains only polyimide.

[0037] As the "porous membrane in which adjacent spherical cells are in communication with each other", it is particularly preferable that 95% by mass or more of the entire porous membrane is at least one of polyimide and polyamideimide. That is, it is preferable that the filter is provided with a porous membrane (polyimide-based resin porous membrane) containing a polyimide-based resin as a resin and in which adjacent spherical cells are in communication with each other.

[0038] ·Polyimide resin porous membrane The polyimide resin may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and an --NH-- bond. The polyimide resin preferably has the functional group at a position other than the main chain end.Preferable examples of the polyimide resin having the functional group at a position other than the main chain end include polyamic acid.

[0039] In this specification, the term "salt-type carboxy group" refers to a group in which a hydrogen atom in a carboxy group is replaced with a cationic moiety. The "cationic moiety" may be a cation itself in a completely ionized state, or may be -COO -The cationic component may be in an ionically bonded state with the cation, which is essentially uncharged, or may be in an intermediate state between the two, which is a cationic component having a partial charge. When the "cation component" is an M ion component consisting of an n-valent metal M, the cation itself is M n+ The cationic component is "-COOM 1 / n "M" in 1 / n " is an element represented by

[0040] The "cation component" includes a cation that is generated when a compound that can be contained in the etching solution described below is ionically dissociated. Representative examples include an ion component or an organic alkali ion component. For example, when the alkali metal ion component is a sodium ion component, the cation itself is a sodium ion (Na + ) and the cationic component is the element represented by "Na" in "-COONa". The cationic component with partial charge is Na δ+ It is. The cationic component is not particularly limited, and may be an inorganic component; NH4 + , N(CH3)4 + Examples of the inorganic components include metal elements such as alkali metals such as Li, Na, and K; and alkaline earth metals such as Mg and Ca. Examples of the organic components include organic alkali ion components. Examples of the organic alkali ion components include NH4 + , e.g. NR4 + (All four R's represent organic groups and may be the same or different.) The organic group of R is preferably an alkyl group, more preferably an alkyl group having 1 to 6 carbon atoms. Examples of the quaternary ammonium cation include N(CH3)4 + etc.

[0041] The state of the cationic component in the salt-type carboxyl group is not particularly limited, and usually depends on the environment in which the polyimide resin exists, for example, whether it is in an aqueous solution, an organic solvent, or dry. When the cationic component is a sodium ion component, for example, in an aqueous solution, it is represented by -COO - and Na + If the solution is in an organic solvent or dry, -COONa is likely not dissociated.

[0042] The polyimide resin may have at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and an -NH- bond, but when it has at least one of these, it usually has both a carboxy group and / or a salt-type carboxy group and an -NH- bond. With respect to the carboxy group and / or the salt-type carboxy group, the polyimide resin may have only a carboxy group, only a salt-type carboxy group, or both a carboxy group and a salt-type carboxy group. The ratio of the carboxy group and the salt-type carboxy group in the polyimide resin may vary depending on, for example, the environment in which the polyimide resin exists, even if it is the same polyimide resin, and is also affected by the concentration of the cationic component.

[0043] The total molar number of the carboxy groups and salt-type carboxy groups contained in the polyimide resin is usually equimolar to the --NH-- bonds in the case of polyimide. In particular, in the method for producing a polyimide porous film described below, when a carboxy group and / or a salt-type carboxy group are formed from a part of the imide bond in the polyimide, an -NH- bond is also formed substantially at the same time. The total number of moles of the carboxy group and the salt-type carboxy group formed is equimolar to the -NH- bond formed. In the case of a method for producing a polyamideimide porous film, the total molar number of carboxy groups and salt-type carboxy groups in the polyamideimide is not necessarily equimolar to the --NH- bonds, but depends on the conditions of chemical etching in the etching (ring-opening of imide bonds) step described below.

[0044] The polyimide resin preferably has at least one type of structural unit selected from the group consisting of structural units represented by the following general formulas (1) to (4). In the case of a polyimide, it is preferable that the polyimide has at least one type of constituent unit selected from the group consisting of a constituent unit represented by the following general formula (1) and a constituent unit represented by the following general formula (2). In the case of a polyamideimide, it is preferable that the polyamideimide has at least one type of constituent unit selected from the group consisting of a constituent unit represented by the following general formula (3) and a constituent unit represented by the following general formula (4).

[0045] [ka]

[0046] [ka]

[0047] In the above formulas (1) to (3), X 1 ~X 4 may be the same or different and are hydrogen atoms or cationic moieties. R Ar is an aryl group, and is a carbonyl group bonded to a structural unit represented by formula (5) constituting a polyamic acid (described later) or a structural unit represented by formula (6) constituting an aromatic polyimide. Ar The aryl group may be the same as the aryl group represented by the following formula: Y 1 ~Y 4 are each independently a divalent residue obtained by removing an amino group from a diamine compound, and are each an R' to which N is bonded in a structural unit represented by formula (5) constituting a polyamic acid described below, or a structural unit represented by formula (6) constituting an aromatic polyimide. Ar The arylene group may be the same as that represented by the following formula:

[0048] The polyimide-based resin may be one in which a portion of the imide bonds (-N[-C(=O)]2) in a general polyimide or polyamideimide is ring-opened to have each constituent unit represented by the above general formula (1) or (2) in the case of a polyimide, or a constituent unit represented by the above general formula (3) in the case of a polyamideimide.

[0049] The polyimide-based resin porous membrane may contain a polyimide-based resin having at least one functional group selected from the group consisting of a carboxy group, a salt-type carboxy group, and an -NH- bond, which is formed by ring-opening a portion of the imide bonds.

[0050] The unchanged rate when a part of the imide bonds is opened can be determined by the following steps (1) to (3). Step (1): For a polyimide resin porous membrane that has not been subjected to the etching (ring-opening of imide bonds) process described below (however, when the varnish for producing the porous membrane contains polyamic acid, the imidization reaction is deemed to have been substantially completed in the process of baking the unbaked composite membrane), a value (X01) is calculated by dividing the area of ​​the peak representing imide bonds measured by a Fourier transform infrared spectrometer (FT-IR) by the area of ​​the peak representing benzene measured by the same FT-IR device. Step (2): A polyimide-based resin porous membrane is obtained by using the same polymer (varnish) as the porous membrane for which the above-mentioned value (X01) was obtained, and the polyimide-based resin porous membrane is subjected to the etching process (ring-opening of imide bonds) described below. The polyimide-based resin porous membrane is then subjected to the etching process (ring-opening of imide bonds) described below. The value (X02) is calculated by dividing the area of ​​the peak representing imide bonds measured by a Fourier transform infrared spectroscopy (FT-IR) device by the area of ​​the peak representing benzene measured by the same FT-IR device. Step (3): Calculate the unchanged rate using the following formula. Unchanged rate (%) = (X02) ÷ (X01) × 100

[0051] The polyimide-based resin porous membrane preferably has a retention rate of 60% or more, more preferably 70 to 99.5%, and even more preferably 80 to 99%. In the case of a porous film containing polyamideimide, since it contains --NH-- bonds, the rate of change may be 100%.

[0052] In the case of a polyimide porous film, the "imidization ratio" is the value obtained by dividing the area of ​​the peak representing the imide bond measured by an FT-IR device by the area of ​​the peak representing benzene also measured by the FT-IR device. The imidization ratio for the value (X02) obtained in the above procedure (2) is preferably 1.2 or more, more preferably 1.2 to 2, even more preferably 1.3 to 1.6, particularly preferably 1.30 to 1.55, and most preferably 1.35 or more and less than 1.5. The imidization ratio for the value (X01) obtained in the above procedure (1) is preferably 1.5 or more. The larger the imidization ratio, the greater the number of imide bonds, that is, the fewer the above-mentioned ring-opened imide bonds.

[0053] Method for manufacturing polyimide-based resin porous membrane The polyimide-based resin porous membrane can be produced by a method including a step of forming carboxy groups and / or salt-type carboxy groups from some of the imide bonds in the polyimide and / or polyamideimide (hereinafter referred to as the "etching step"). In the etching step, when carboxy groups and / or salt-type carboxy groups are formed from a portion of the imide bonds, theoretically equimolar --NH-- bonds are also formed substantially simultaneously with these groups.

[0054] When the resin that polyimide-based resin porous membrane contains is substantially made of polyamideimide, the porous membrane already has -NH- bond without carrying out etching process, and shows good adsorption power to foreign matter in the object to be filtered.In this case, etching process is not necessarily required because it is not particularly necessary to slow down the flow rate of the object to be filtered, but it is preferable to provide etching process in order to achieve the object of the present invention more effectively.

[0055] A preferred method for producing a polyimide-based resin porous membrane is to produce a formed membrane containing polyimide and / or polyamideimide as a main component (hereinafter sometimes abbreviated as "polyimide-based resin formed membrane") and then carry out an etching step. The polyimide resin film to be subjected to the etching step may be either porous or non-porous. The form of the polyimide-based resin molded film is not particularly limited, but is preferably a thin form such as a film, in order to increase the degree of porosity in the resulting polyimide-based resin porous film, and is more preferably porous and thin in form such as a film.

[0056] As described above, the polyimide-based resin film may be non-porous when the etching step is carried out, but in this case, it is preferable to make the film porous after the etching step. As a method for making a polyimide-based resin molded film porous before or after the etching step, a method including a step of removing fine particles from a composite film of polyimide and / or polyamideimide and fine particles (hereinafter referred to as a "polyimide-based resin-fine particle composite film") to make the film porous is preferable.

[0057] The method for producing the polyimide-based resin porous membrane may be the following production method (a) or (b). Manufacturing method (a): A method in which an etching step is performed on a composite film of polyimide and / or polyamideimide and fine particles before the [fine particle removal] step. Manufacturing method (b): A method in which, after the step of [removing fine particles], an etching step is carried out on the polyimide-based resin film that has been made porous by the step. Among these, the latter production method (b) is preferred since it is possible to further increase the degree of porosity in the resulting polyimide resin porous membrane.

[0058] An example of a method for producing a polyimide-based resin porous membrane will be described below.

[0059] [Preparation of varnish] A varnish is prepared by mixing a microparticle dispersion in which microparticles are previously dispersed in an organic solvent with polyamic acid, polyimide, or polyamideimide in any ratio, or by polymerizing a tetracarboxylic dianhydride and a diamine in the microparticle dispersion to form a polyamic acid, or by further imidizing the polyamic acid to form a polyimide. The viscosity of the varnish is preferably 300 to 2000 cP (0.3 to 2 Pa·s), and more preferably 400 to 1800 cP (0.4 to 1.8 Pa·s). If the viscosity of the varnish is within the above range, a more uniform film can be formed. The viscosity of the varnish can be measured at a temperature of 25° C. using an E-type rotational viscometer.

[0060] In the varnish, resin fine particles and polyamic acid, polyimide, or polyamideimide are mixed so that when the varnish is baked (or dried if baking is optional) to form a polyimide-based resin-fine particle composite film, the fine particle / polyimide-based resin ratio is preferably 1 to 4 (mass ratio), and more preferably 1.1 to 3.5 (mass ratio). Furthermore, when a polyimide-based resin-particle composite film is formed, the particles are mixed with polyamic acid, polyimide, or polyamideimide so that the volume ratio of particles / polyimide-based resin is preferably 1.1 to 5, and more preferably 1.1 to 4.5. When the mass ratio or volume ratio is equal to or greater than the preferred lower limit of the range, a pore density appropriate for a porous membrane can be easily obtained, and when the mass ratio or volume ratio is equal to or less than the preferred upper limit of the range, problems such as an increase in viscosity or cracks in the membrane are unlikely to occur, and the membrane can be stably formed. In this specification, the volume ratios are values ​​at 25°C.

[0061] ...fine particles There are no particular limitations on the material of the fine particles, so long as it is insoluble in the organic solvent used in the varnish and can be selectively removed after film formation. Examples of the material of the fine particles include inorganic materials such as silica (silicon dioxide), titanium oxide, alumina (Al2O3), and metal oxides such as calcium carbonate. Examples of the organic materials include organic polymers such as high molecular weight olefins (polypropylene, polyethylene, etc.), polystyrene, acrylic resins (methyl methacrylate, isobutyl methacrylate, polymethyl methacrylate (PMMA), etc.), epoxy resins, cellulose, polyvinyl alcohol, polyvinyl butyral, polyester, polyether, and polyethylene. Among these, silica such as colloidal silica is preferred as the inorganic material, since minute pores having curved inner surfaces are easily formed in the porous film, and acrylic resins such as PMMA are preferred as the organic material.

[0062] The resin particles can be selected from, for example, ordinary linear polymers and known depolymerizable polymers without any particular limitation depending on the purpose. Ordinary linear polymers are polymers whose molecular chains are randomly cut upon thermal decomposition. Depolymerizable polymers are polymers whose polymers are decomposed into monomers upon thermal decomposition. Any of the polymers can be removed from the polyimide resin film by being decomposed into monomers, low molecular weight substances, or CO2 upon heating.

[0063] Among the depolymerizable polymers, from the viewpoint of handling during pore formation, methyl methacrylate or isobutyl methacrylate alone (polymethyl methacrylate or polyisobutyl methacrylate), which have a low thermal decomposition temperature, or a copolymer having these as the main component, is preferred.

[0064] The decomposition temperature of the resin fine particles is preferably 200 to 320° C., more preferably 230 to 260° C. If the decomposition temperature is 200° C. or higher, film formation can be performed even when a high boiling point solvent is used in the varnish, and the range of baking conditions for the polyimide resin can be broadened. If the decomposition temperature is 320° C. or lower, only the resin fine particles can be easily eliminated without thermally damaging the polyimide resin.

[0065] The fine particles preferably have a high sphericity, since the inner surfaces of the pores in the porous film formed are likely to have curved surfaces. The particle size (average diameter) of the fine particles used is, for example, preferably 20 to 2500 nm, more preferably 30 to 1000 nm, and further preferably 50 to 250 nm. When the average diameter of the fine particles is within the above range, when the object to be filtered is passed through the polyimide resin porous membrane obtained by removing the fine particles, the object to be filtered can be brought into even contact with the inner surfaces of the pores in the porous membrane, and foreign matter contained in the object to be filtered can be adsorbed efficiently.

[0066] The particle size distribution index (d25 / d75) of the fine particles is preferably 1-6, more preferably 1.6-5, and further preferably 2-4. By setting the particle size distribution index to the preferable lower limit of the range or more, the fine particles can be efficiently packed inside the porous membrane, so that the flow path is easily formed and the flow rate is improved. In addition, holes of different sizes are easily formed, and different convection currents are generated, so that the adsorption rate of foreign matter is further improved. Incidentally, d25 and d75 are the particle size values ​​at which the cumulative frequency of the particle size distribution is 25% and 75%, respectively, and in this specification, d25 is the larger particle size.

[0067] In the below-described [Formation of Unbaked Composite Film], when the unbaked composite film is formed in two layers, the fine particles (B1) used in the first varnish and the fine particles (B2) used in the second varnish may be the same or different. In order to make the pores on the side in contact with the substrate denser, the fine particles (B1) preferably have a particle size distribution index smaller than or equal to that of the fine particles (B2). Alternatively, the fine particles (B1) preferably have a sphericity smaller than or equal to that of the fine particles (B2). In addition, the fine particles (B1) preferably have a particle size (average diameter) smaller than that of the fine particles (B2), and it is particularly preferable to use fine particles (B1) having a particle size (average diameter) of 100 to 1000 nm (more preferably 100 to 600 nm) and fine particles (B2) having a particle size (average diameter) of 500 to 2000 nm (more preferably 700 to 2000 nm). By using fine particles (B1) having a smaller particle size than fine particles (B2), the opening ratio of the pores on the surface of the obtained polyimide-based resin porous membrane can be increased and the diameter of the pores can be made uniform, and the strength of the entire polyimide-based resin porous membrane can be increased compared to when the membrane is made of fine particles (B1) alone.

[0068] In this embodiment, a dispersant may be added to the varnish together with the fine particles in order to disperse the fine particles uniformly. By adding a dispersant, the polyamic acid or polyimide or polyamideimide can be mixed with the fine particles more uniformly, and the fine particles can be distributed uniformly in the unsintered composite film. As a result, dense openings are provided on the surface of the finally obtained polyimide-based resin porous film, and it is possible to efficiently form communicating holes that communicate the front and back surfaces of the porous film so that the air permeability of the polyimide-based resin porous film is improved.

[0069] The dispersant is not particularly limited, and known dispersants can be used. Examples of the dispersant include anionic surfactants such as coconut fatty acid salts, castor oil sulfate salts, lauryl sulfate salts, polyoxyalkylene allyl phenyl ether sulfate salts, alkylbenzene sulfonic acid, alkylbenzene sulfonate salts, alkyl diphenyl ether disulfonate salts, alkyl naphthalene sulfonate salts, dialkyl sulfosuccinate salts, isopropyl phosphate, polyoxyethylene alkyl ether phosphate salts, and polyoxyethylene allyl phenyl ether phosphate salts; cationic surfactants such as oleylamine acetate, lauryl pyridinium chloride, cetyl pyridinium chloride, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, and didecyl dimethyl ammonium chloride; amphoteric surfactants such as coconut alkyl dimethyl amine oxide, fatty acid amidopropyl dimethyl amine oxide, alkyl polyaminoethyl glycine hydrochloride, amido betaine type surfactants, alanine type surfactants, and lauryl imino dipropionic acid. Surfactants include polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene laurylamine, polyoxyethylene oleylamine, polyoxyethylene polystyrylphenyl ether, polyoxyalkylene polystyrylphenyl ether and other polyoxyalkylene primary alkyl ether or polyoxyalkylene secondary alkyl ether nonionic surfactants, polyoxyethylene dilaurate, polyoxyethylene laurate, polyoxyethylated castor oil, polyoxyethylated hydrogenated castor oil, sorbitan laurate, polyoxyethylene sorbitan laurate, fatty acid diethanolamide and other polyoxyalkylene-based nonionic surfactants; fatty acid alkyl esters such as octyl stearate and trimethylolpropane tridecanoate; and polyether polyols such as polyoxyalkylene butyl ether, polyoxyalkylene oleyl ether and trimethylolpropane tris(polyoxyalkylene) ether.The above dispersants can be used alone or in combination of two or more.

[0070] Polyamic acid The polyamic acid that can be used in the present embodiment includes those obtained by polymerizing any tetracarboxylic dianhydride and diamine.

[0071] Tetracarboxylic acid dianhydride The tetracarboxylic dianhydride can be appropriately selected from tetracarboxylic dianhydrides that have been conventionally used as a raw material for synthesizing polyamic acid. The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or an aliphatic tetracarboxylic dianhydride.

[0072] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2,6,6-biphenyltetracarbo dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 3,3',4,4'-benzophenone tetracarboxamide dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 4,4-(p-phenylenedioxy)diphthalic dianhydride, 4,4-(m-phenylenedioxy)diphthalic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bisphthalic acid fluorene anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and the like.

[0073] Examples of the aliphatic tetracarboxylic dianhydride include ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarboxylic dianhydride, cyclohexane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, and 1,2,3,4-cyclohexane tetracarboxylic dianhydride.

[0074] Among the above, aromatic tetracarboxylic dianhydrides are preferred from the viewpoint of the heat resistance of the resulting polyimide resin, and among these, 3,3',4,4'-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride are preferred from the viewpoints of price, availability, etc. The tetracarboxylic dianhydrides can be used alone or in combination of two or more.

[0075] ...Diamine The diamine can be appropriately selected from diamines that have been used as a synthetic raw material for polyamic acid. The diamine may be an aromatic diamine or an aliphatic diamine, but from the viewpoint of the heat resistance of the resulting polyimide resin, aromatic diamines are preferred. The diamine can be used alone or in combination of two or more.

[0076] The aromatic diamine may be a diamino compound having one or about 2 to 10 phenyl groups bonded thereto. Specific examples of the aromatic diamine include phenylenediamine or a derivative thereof, a diaminobiphenyl compound or a derivative thereof, a diaminodiphenyl compound or a derivative thereof, a diaminotriphenyl compound or a derivative thereof, a diaminonaphthalene or a derivative thereof, an aminophenylaminoindan or a derivative thereof, a diaminotetraphenyl compound or a derivative thereof, a diaminohexaphenyl compound or a derivative thereof, and a cardo-type fluorenediamine derivative.

[0077] The phenylenediamine is preferably m-phenylenediamine or p-phenylenediamine. The phenylenediamine derivative includes diamines having an alkyl group such as a methyl group or an ethyl group bonded thereto, such as 2,4-diaminotoluene and 2,4-triphenylenediamine.

[0078] A diaminobiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via a phenyl group. Examples of the diaminobiphenyl compound include 4,4'-diaminobiphenyl and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl.

[0079] The diaminodiphenyl compound is a compound in which two aminophenyl groups are bonded to each other via another group. Examples of the other group include an ether bond, a sulfonyl bond, a thioether bond, an alkylene group or a derivative group thereof, an imino bond, an azo bond, a phosphine oxide bond, an amide bond, and a ureylene bond. The alkylene group preferably has about 1 to 6 carbon atoms, and the derivative group is a compound in which one or more hydrogen atoms of the alkylene group are substituted with a halogen atom or the like.

[0080] Examples of diaminodiphenyl compounds include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl methane, 3,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2-bis(p-aminophenyl)propane, 2,2'-bis(p-aminophenyl)hexafluoropropane, 4-methyl-2,4-bis(p-aminophenyl)-1-pentene, 4-methyl-2,4-bis(p-aminophenyl) )-2-pentene, iminodianiline, 4-methyl-2,4-bis(p-aminophenyl)pentane, bis(p-aminophenyl)phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-diaminodiphenylamide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and the like.

[0081] The diaminotriphenyl compound is a compound in which two aminophenyl groups and one phenylene group are bonded via other groups, which are the same as the other groups in the diaminodiphenyl compound. Examples of the diaminotriphenyl compound include 1,3-bis(m-aminophenoxy)benzene, 1,3-bis(p-aminophenoxy)benzene, and 1,4-bis(p-aminophenoxy)benzene.

[0082] Examples of diaminonaphthalene include 1,5-diaminonaphthalene and 2,6-diaminonaphthalene.

[0083] Examples of the aminophenylaminoindan include 5- or 6-amino-1-(p-aminophenyl)-1,3,3-trimethylindan.

[0084] Examples of diaminotetraphenyl compounds include 4,4'-bis(p-aminophenoxy)biphenyl, 2,2'-bis[p-(p'-aminophenoxy)phenyl]propane, 2,2'-bis[p-(p'-aminophenoxy)biphenyl]propane, and 2,2'-bis[p-(m-aminophenoxy)phenyl]benzophenone.

[0085] Examples of cardo-type fluorenediamine derivatives include 9,9-bisanilinefluorene.

[0086] The aliphatic diamine is preferably one having about 2 to 15 carbon atoms, and specific examples thereof include pentamethylenediamine, hexamethylenediamine, and heptamethylenediamine.

[0087] Incidentally, the diamine may be a compound in which a hydrogen atom is substituted with at least one substituent selected from the group consisting of a halogen atom, a methyl group, a methoxy group, a cyano group, and a phenyl group.

[0088] Among the above, the diamine is preferably phenylenediamine, a phenylenediamine derivative, or a diaminodiphenyl compound, and among these, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, or 4,4'-diaminodiphenyl ether is particularly preferred from the standpoint of cost, availability, etc.

[0089] The method for producing the polyamic acid is not particularly limited, and a known method such as a method of reacting any tetracarboxylic dianhydride with a diamine in an organic solvent can be used. The reaction between the tetracarboxylic dianhydride and the diamine is usually carried out in an organic solvent. The organic solvent used here is not particularly limited as long as it can dissolve the tetracarboxylic dianhydride and the diamine, and does not react with the tetracarboxylic dianhydride and the diamine. The organic solvent can be used alone or in combination of two or more kinds.

[0090] Examples of organic solvents used in the reaction between tetracarboxylic dianhydride and diamine include nitrogen-containing polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, and N,N,N',N'-tetramethylurea; lactone-based polar solvents such as β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, and ε-caprolactone; dimethyl sulfoxide; acetonitrile; fatty acid esters such as ethyl lactate and butyl lactate; ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, tetrahydrofuran, methyl cellosolve acetate, and ethyl cellosolve acetate; and phenolic solvents such as cresols.

[0091] Among these, it is preferable to use a nitrogen-containing polar solvent as the organic solvent here from the viewpoint of the solubility of the produced polyamic acid. From the viewpoint of film-forming properties, etc., it is preferable to use a mixed solvent containing a lactone polar solvent. In this case, the content of the lactone polar solvent is preferably 1 to 20 mass %, more preferably 5 to 15 mass %, based on the total organic solvent (100 mass %). The organic solvent used here is preferably one or more selected from the group consisting of nitrogen-containing polar solvents and lactone-based polar solvents, and more preferably a mixed solvent of a nitrogen-containing polar solvent and a lactone-based polar solvent. The amount of the organic solvent used is not particularly limited, but is preferably such that the content of the produced polyamic acid in the reaction liquid after the reaction is about 5 to 50% by mass.

[0092] The amounts of the tetracarboxylic dianhydride and the diamine used are not particularly limited, but it is preferable to use 0.50 to 1.50 mol of the diamine per 1 mol of the tetracarboxylic dianhydride, more preferably 0.60 to 1.30 mol, and particularly preferably 0.70 to 1.20 mol.

[0093] The reaction (polymerization) temperature is generally from -10 to 120°C, preferably from 5 to 30°C. The reaction (polymerization) time varies depending on the composition of the raw materials used, but is usually 3 to 24 (hours). The intrinsic viscosity of the polyamic acid solution obtained under such conditions is preferably in the range of 1,000 to 100,000 cP (centipoise) (1 to 100 Pa·s), and more preferably 5,000 to 70,000 cP (5 to 70 Pa·s). The intrinsic viscosity of the polyamic acid solution can be measured at a temperature of 25° C. using an E-type rotational viscometer.

[0094] Polyimide The polyimide that can be used in this embodiment is not limited in structure or molecular weight, and any known polyimide can be used as long as it is soluble in the organic solvent used in the varnish. The polyimide may have, in its side chain, a functional group capable of condensation, such as a carboxyl group, or a functional group that promotes a crosslinking reaction or the like upon baking.

[0095] In order to make the polyimide soluble in the organic solvent used in the varnish, it is effective to use a monomer for introducing a flexible, bent structure into the main chain. Examples of this monomer include aliphatic diamines such as ethylenediamine, hexamethylenediamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, and 4,4'-diaminodicyclohexylmethane; aromatic diamines such as 2-methyl-1,4-phenylenediamine, o-tolidine, m-tolidine, 3,3'-dimethoxybenzidine, and 4,4'-diaminobenzanilide; polyoxyalkylene diamines such as polyoxyethylenediamine, polyoxypropylenediamine, and polyoxybutylenediamine; polysiloxane diamines; 2,3,3',4'-oxydiphthalic anhydride, 3,4,3',4'-oxydiphthalic anhydride, and 2,2-bis(4-hydroxyphenyl)propanedibenzoate-3,3',4,4'-tetracarboxylic dianhydride.

[0096] It is also effective to use a monomer having a functional group that improves the solubility in such organic solvents. Examples of such monomers having a functional group include fluorinated diamines such as 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl and 2-trifluoromethyl-1,4-phenylenediamine. Furthermore, in addition to such a monomer having a functional group, the monomers exemplified in the description of the polyamic acid above can also be used in combination, provided that the solubility is not impaired.

[0097] The method for producing the polyimide is not particularly limited, and examples thereof include known methods such as a method in which polyamic acid is chemically imidized or thermally imidized, and then dissolved in an organic solvent.

[0098] Examples of polyimides that can be used in this embodiment include aliphatic polyimides (all aliphatic polyimides) and aromatic polyimides, and among these, aromatic polyimides are preferred. The aromatic polyimide may be one obtained by subjecting a polyamic acid having a constitutional unit represented by the following general formula (5) to a thermal or chemical ring-closing reaction, or one obtained by dissolving a polyimide having a constitutional unit represented by the following general formula (6) in a solvent. In the formula, R Aris an aryl group, R' Ar represents an arylene group.

[0099] [ka]

[0100] In the above formula, R Ar is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Among them, R Ar is preferably an aromatic hydrocarbon ring, more preferably benzene or naphthalene, and particularly preferably benzene. In the above formula, R' Ar is the above R Ar In particular, R' is a group in which two hydrogen atoms have been removed from the aromatic ring. Ar is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring, more preferably a group in which two hydrogen atoms have been removed from benzene or naphthalene, and particularly preferably a phenylene group in which two hydrogen atoms have been removed from benzene. R Ar The aryl group in R' Ar Each of the arylene groups in the formula (I) may have a substituent.

[0101] Polyamide-imide The polyamideimide that can be used in this embodiment is not limited in structure or molecular weight, and any known polyamideimide can be used as long as it is soluble in the organic solvent used in the varnish. The polyamideimide may have, in its side chain, a functional group capable of condensation, such as a carboxy group, or a functional group that promotes a crosslinking reaction or the like during baking.

[0102] Such polyamideimides can be used without any particular limitation, including those obtained by reacting any trimellitic anhydride with a diisocyanate, and those obtained by imidizing a precursor polymer obtained by reacting any reactive derivative of trimellitic anhydride with a diamine.

[0103] Examples of the above-mentioned optional reactive derivatives of trimellitic anhydride include trimellitic anhydride halides such as trimellitic anhydride chloride, and trimellitic anhydride esters.

[0104] Examples of the optional diisocyanate include metaphenylene diisocyanate, p-phenylene diisocyanate, o-tolidine diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, 4,4'-oxybis(phenylisocyanate), 4,4'-diisocyanate diphenylmethane, bis[4-(4-isocyanate phenoxy)phenyl]sulfone, 2,2'-bis[4-(4-isocyanate phenoxy)phenyl]propane, 2,4 -tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 3,3'-diethyldiphenyl-4,4'-diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, naphthalene diisocyanate, and the like.

[0105] The optional diamine may be the same as the diamines exemplified in the description of the polyamic acid.

[0106] ...Organic solvents The organic solvent that can be used in preparing the varnish is not particularly limited as long as it can dissolve the polyamic acid and / or polyimide resin and does not dissolve the fine particles, and examples of the organic solvent that can be used in the reaction of the tetracarboxylic dianhydride with the diamine include the same organic solvents as those used in the reaction of the tetracarboxylic dianhydride with the diamine. The organic solvents may be used alone or in combination of two or more.

[0107] The content of the organic solvent in the varnish is preferably 50 to 95% by mass, more preferably 60 to 85% by mass. The solid content concentration in the varnish is preferably 5 to 50% by mass, more preferably 15 to 40% by mass.

[0108] In the later-described [Formation of Unbaked Composite Film], when the unbaked composite film is formed as a two-layer film, the volume ratio of polyamic acid or polyimide or polyamideimide to fine particles (B1) in the first varnish is preferably 19:81 to 45:55. When the volume ratio of the fine particles (B1) is taken as 100, if it is 55 or more, the particles are uniformly dispersed, and if it is 81 or less, the particles are easily dispersed without agglomerating with each other. This allows holes to be uniformly formed on the side surface of the substrate in the polyimide-based resin formed film. The volume ratio of the polyamic acid or polyimide or polyamideimide (A2) to the fine particles (B2) in the second varnish is preferably 20:80 to 50:50. When the volume ratio of the fine particles (B2) is taken as 100, if it is 50 or more, the particles are easily uniformly dispersed, and if it is 80 or less, the particles do not aggregate with each other and cracks are unlikely to occur on the surface. This makes it easier to form a polyimide-based resin porous membrane with good mechanical properties such as stress and elongation at break.

[0109] Regarding the volume ratio, the second varnish preferably has a lower fine particle content than the first varnish. By satisfying the above conditions, even if the fine particles are highly filled in the polyamic acid, polyimide, or polyamideimide, the strength and flexibility of the unsintered composite film, the polyimide-based resin-fine particle composite film, and the polyimide-based resin porous film are ensured. In addition, by providing a layer with a low fine particle content, the manufacturing cost can be reduced.

[0110] When preparing the varnish, in addition to the components described above, known components such as antistatic agents, flame retardants, chemical imidization agents, condensation agents, release agents, and surface conditioners may be blended as necessary for the purposes of antistatic properties, imparting flame retardancy, low-temperature baking, releasability, coatability, and the like.

[0111] [Deposition of unsintered composite film] The formation of an unsintered composite film containing polyamic acid or polyimide or polyamideimide and fine particles is carried out, for example, by applying the above-mentioned varnish onto a substrate and drying it under normal pressure or vacuum at 0 to 120°C (preferably 0 to 100°C), more preferably at normal pressure and 60 to 95°C (even more preferably 65 to 90°C). The coating thickness is, for example, preferably 1 to 500 μm, more preferably 5 to 50 μm.

[0112] If necessary, a release layer may be provided on the substrate. In addition, in forming the green composite film, a step of immersing in a solvent containing water, a drying step, and a pressing step may be optionally performed before the step of [Firing the green composite film] described later.

[0113] The release layer can be prepared by applying a release agent onto the substrate and drying or baking the applied agent. The release agent used here can be any known release agent, such as an alkyl ammonium phosphate release agent, a fluorine-based release agent, or a silicone-based release agent, without any particular limitation. When the unsintered composite film after drying is peeled off from the substrate, a small amount of release agent remains on the peeled surface of the unsintered composite film. This remaining release agent may affect the wettability of the polyimide-based resin porous film surface and the inclusion of impurities, so it is preferable to remove it. Therefore, it is preferable to wash the unsintered composite film peeled off from the substrate with an organic solvent, etc. Examples of the washing method include a known method such as a method of immersing the unsintered composite film in a washing liquid and then removing it, and a shower washing method. In order to dry the unsintered composite film after washing, for example, the unsintered composite film after washing is air-dried at room temperature or heated to an appropriate set temperature in a thermostatic chamber. In this case, for example, a method of fixing the ends of the unsintered composite film to a SUS mold or the like to prevent deformation can be adopted.

[0114] On the other hand, in the case where the substrate is used as it is without providing a release layer in forming the green composite film, the step of forming the release layer and the step of washing the green composite film can be omitted.

[0115] Furthermore, when forming an unsintered composite film in a two-layer structure, first, the above-mentioned first varnish is directly applied onto a substrate such as a glass substrate, and then dried under normal pressure or vacuum at 0 to 120°C (preferably 0 to 90°C), more preferably at normal pressure and 10 to 100°C (even more preferably 10 to 90°C) to form a first unsintered composite film having a thickness of 1 to 5 μm. Next, the second varnish is applied onto the first unsintered composite film, and similarly dried under conditions of 0 to 80°C (preferably 0 to 50°C), more preferably 10 to 80°C (even more preferably 10 to 30°C) at normal pressure, to form a second unsintered composite film having a thickness of 5 to 50 μm, thereby forming a two-layered unsintered composite film.

[0116] [Firing of unfired composite film] After the above [Formation of unsintered composite film], the unsintered composite film is subjected to a heat treatment (sintering) to form a composite film (polyimide resin-particle composite film) consisting of the polyimide resin and the particles. When the varnish contains a polyamic acid, it is preferable to complete the imidization in this step [baking the unbaked composite film].

[0117] The temperature for the heat treatment (baking temperature) varies depending on the structure of the polyamic acid, polyimide or polyamideimide contained in the unbaked composite film and the presence or absence of a condensing agent, but is preferably 120 to 400°C, more preferably 150 to 375°C.

[0118] The firing process does not necessarily have to be clearly separated from the drying process in the previous step. For example, when firing at 375°C, a method of raising the temperature from room temperature to 375°C in 3 hours and then holding at 375°C for 20 minutes, or a stepwise drying-thermal imidization method of raising the temperature from room temperature to 375°C in increments of 50°C (holding for 20 minutes at each increment) and finally holding at 375°C for 20 minutes can be used. In this case, a method of fixing the ends of the unfired composite film to a SUS mold or the like to prevent deformation can be used.

[0119] The thickness of the polyimide-based resin-particle composite film after heat treatment (baking) is, for example, preferably 1 μm or more, more preferably 5 to 500 μm, and even more preferably 8 to 100 μm. The thickness of the polyimide-based resin-fine particle composite film can be determined by measuring the thickness at multiple locations using a micrometer and averaging the measured values.

[0120] This step is optional, and may not be performed, particularly when polyimide or polyamideimide is used in the varnish.

[0121] [Removal of fine particles] After the above [sintering of the unsintered composite film], the fine particles are removed from the polyimide resin-fine particle composite film to produce a polyimide resin porous film. For example, when silica is used as the fine particles, the silica is dissolved and removed by contacting the polyimide resin-fine particle composite film with low-concentration hydrogen fluoride (HF) water to obtain a porous film. When the fine particles are resin fine particles, the resin fine particles are decomposed and removed by heating to a temperature equal to or higher than the thermal decomposition temperature of the resin fine particles and lower than the thermal decomposition temperature of the polyimide resin to obtain a porous film.

[0122] [Etching (opening of imide bonds)] The etching step can be carried out by a chemical etching method or a physical removal method, or a combination of these methods.

[0123] Chemical Etching Method As the chemical etching method, a conventionally known method can be used. The chemical etching method is not particularly limited, and examples thereof include treatment with an etching solution such as an inorganic alkaline solution or an organic alkaline solution, etc. Among these, treatment with an inorganic alkaline solution is preferred. Examples of inorganic alkaline solutions include hydrazine solutions containing hydrazine hydrate and ethylenediamine; solutions of alkali metal hydroxides such as potassium hydroxide, sodium hydroxide, sodium carbonate, sodium silicate, and sodium metasilicate; ammonia solutions; and etching solutions containing alkali hydroxides, hydrazine, and 1,3-dimethyl-2-imidazolidinone as main components. Examples of the organic alkaline solution include alkaline etching solutions such as primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and cyclic amines such as pyrrole and piheridine. The alkali concentration in the etching solution is, for example, 0.01 to 20% by mass.

[0124] The solvent for each of the above etching solutions may be selected from pure water and alcohols as appropriate, and a suitable amount of a surfactant may also be added to the solution.

[0125] Physical removal methods The physical removal method may be, for example, a dry etching method using plasma (oxygen, argon, etc.), corona discharge, or the like.

[0126] The above-mentioned chemical etching method or physical removal method can be applied before or after the above-mentioned [removal of fine particles]. Among these, it is preferable to apply this method after the above-mentioned "removal of fine particles" since this makes it easier to form internal continuous pores in the polyimide-based resin porous membrane and improves the removal of foreign matter.

[0127] When a chemical etching method is used in the etching step, a step of washing the porous polyimide resin membrane may be provided after this step in order to remove excess etching solution. The cleaning after chemical etching may be performed by washing with water alone, but it is preferable to perform an acid cleaning and a water cleaning in combination.

[0128] After the etching step, the polyimide-based resin porous membrane may be subjected to a heat treatment (re-baking) in order to improve the wettability of the surface of the polyimide-based resin porous membrane to an organic solvent and to remove remaining organic matter. The heating conditions are the same as those in the above-mentioned [Baking of the unbaked composite membrane].

[0129] For example, the polyimide-based resin porous membrane produced by the above-mentioned production method has spherical cells and communicating holes that connect adjacent spherical cells, and preferably, the communicating holes that open on one outer surface communicate the inside of the porous membrane and open to the other (rear) outer surface, thereby ensuring a flow path through which a fluid can pass through the porous membrane.

[0130] The Gurley air permeability of the "porous membrane in which adjacent spherical cells are connected to each other" is preferably 30 seconds or more, for example, from the viewpoint of efficiently removing foreign matter while maintaining a relatively high flow rate of the object to be filtered passing through the porous membrane. The Gurley air permeability of the porous membrane is more preferably 30 to 1000 seconds, further preferably 30 to 600 seconds, and particularly preferably 30 to 500 seconds. If the Gurley air permeability is equal to or less than the preferred upper limit of the above range, the degree of porosity (such as the ratio of communicating holes) is sufficiently high, so that the effect of removing foreign matter is more easily obtained. The Gurley air permeability of the porous membrane can be measured in accordance with JIS P 8117.

[0131] The "porous membrane in which adjacent spherical cells are connected to each other" preferably has interconnected pores with an average pore size of 1 to 1000 nm, more preferably 3 to 300 nm, further preferably 5 to 100 nm, and particularly preferably 10 to 80 nm. The pore size of the communicating hole refers to the diameter of the communicating hole. Note that, since one communicating hole is usually formed from two adjacent particles by the above-mentioned production method, the diameter includes, for example, the case where the direction in which the two holes constituting the communicating hole are adjacent to each other is taken as the longitudinal direction and the diameter is taken as the direction perpendicular to the longitudinal direction, and the pore size of the communicating hole tends to be small when the (imide bond ring-opening) step is not provided. The average pore size of the communicating pores formed by the communication between adjacent spherical cells in the porous membrane (also referred to as the average pore size of the porous membrane) is a value measured using a perm porometer (e.g., manufactured by PMI) according to the half-dry method (ASTM E1294-89) using perfluoropolyester (trade name Galwick, interfacial tension value: 15.9 dyne / cm) as a test liquid at a measurement temperature of 25°C and a measurement pressure range of 0 to 400 psi.

[0132] The average pore size of the spherical cells of the "porous film in which adjacent spherical cells are connected to each other" is preferably 10 to 2500 nm, more preferably 20 to 1000 nm, further preferably 30 to 500 nm, and particularly preferably 40 to 400 nm. For porous films that are not chemically etched (e.g., polyamideimide porous films), the average particle size of the microparticles used in the production of the porous film is the average pore size of the spherical cells.

[0133] As described above, the "porous film in which adjacent spherical cells are connected to each other" is a porous film containing pores having an average pore size of several hundreds of nanometers. Therefore, even minute substances, for example, on the nanometer scale, can be adsorbed or captured in the pores and / or the connected pores in the porous film.

[0134] The pore size of such communicating holes tends to be smaller when the distribution of pore sizes of the individual pores that impart porosity to the "porous membrane in which adjacent spherical cells are connected" is broad. From the viewpoint of reducing the pore size of the communicating holes, the porosity of the "porous membrane in which adjacent spherical cells communicate with each other" is, for example, preferably 50% by mass or more, more preferably 55 to 90% by mass, even more preferably 60 to 80% by mass, and particularly preferably about 60 to 70% by mass. If the porosity is equal to or more than the preferable lower limit of the above range, the effect of removing foreign matter is more easily obtained. If the porosity is equal to or less than the preferable upper limit of the above range, the strength of the porous membrane is further increased. The porosity of the porous membrane can be found by calculating the ratio of the mass of the fine particles to the total mass of the resin and the fine particles used in producing the porous membrane.

[0135] The "porous film in which adjacent spherical cells are interconnected" has excellent mechanical properties such as stress and breaking elongation. The stress of the "porous membrane in which adjacent spherical cells communicate with each other" provided in the filter is, for example, preferably 10 MPa or more, more preferably 15 MPa or more, and further preferably 15 to 60 MPa. The stress of the porous film is determined by preparing a sample of 4 mm×30 mm and measuring it using a testing machine at a measuring condition of 5 mm / min.

[0136] The breaking elongation of the "porous membrane in which adjacent spherical cells are connected to each other" is, for example, preferably 10% GL or more, more preferably 15% GL or more. The upper limit of the breaking elongation is, for example, preferably 60% GL or less, more preferably 55% GL or less. When the porosity of the polyimide resin porous membrane is reduced, the breaking elongation tends to increase. The breaking elongation of the porous membrane is determined by preparing a sample of 4 mm×30 mm and measuring it using a testing machine under the measurement condition of 5 mm / min.

[0137] The thermal decomposition temperature of the "porous film in which adjacent spherical cells are connected to each other" is preferably 200°C or higher, more preferably 320°C or higher, and even more preferably 350°C or higher. The thermal decomposition temperature of the porous film can be measured by increasing the temperature to 1000° C. at a rate of 10° C. / min in an air atmosphere.

[0138] The filter in this embodiment is not limited to one having a porous membrane with communicating holes 5 that connect adjacent spherical cells 1a and 1b as shown in Figure 1, but may be one having a porous membrane with cells or communicating holes of other shapes in addition to the communicating holes 5. Cells of other shapes (hereinafter referred to as "other cells") include cells with different shapes or pore sizes, such as elliptical cells, polyhedral cells, spherical cells with different pore sizes, etc. The "communicating holes of other shapes" include, for example, communicating holes in which spherical cells communicate with other cells. The shape or pore size of the other cells may be appropriately determined depending on the type of impurities to be removed. The communicating holes that connect the spherical cells to the other cells can be formed by selecting the material of the particles described above, controlling the shape of the particles, etc. A filter having a porous membrane in which, in addition to the communicating holes connecting adjacent spherical cells, other types of cells or communicating holes are formed, can more efficiently remove various foreign matter from the material to be filtered.

[0139] Furthermore, the filter in this embodiment can be used in place of or in combination with a filter cartridge or the like that has been installed in the supply lines or POU (point of use) of various chemicals in the semiconductor manufacturing process for removing particulate impurities. Therefore, using the same equipment and operation as in the past, various foreign matters can be efficiently removed from the object to be filtered (chemicals for lithography), and a high-purity refined resist composition product can be prepared.

[0140] <Filtering the resist composition> The filtration of the resist composition through a filter having a porous structure in which adjacent spherical cells are connected to each other may be performed without a differential pressure (i.e., the resist composition may be passed through the filter only by gravity) or may be performed with a differential pressure. Among these, the latter is preferred, and it is preferred to perform an operation of passing the resist composition through the filter by a differential pressure.

[0141] The term "state in which a pressure difference is provided" refers to a state in which there is a pressure difference between one side and the other side of a porous polyimide resin membrane provided in a filter. For example, pressurization (positive pressure) is applied to one side (resist composition supply side) of the polyimide-based resin porous membrane, and depressurization (negative pressure) is applied to one side (filtrate side) of the polyimide-based resin porous membrane. In the filtration step of the present embodiment, the former pressurization is preferred.

[0142] The pressurization is performed by applying pressure to the supply liquid side of the polyimide-based resin porous membrane, where the resist composition (hereinafter sometimes referred to as "supply liquid") is present before passing through the polyimide-based resin porous membrane. For example, it is preferable to apply pressure to the supply liquid side by utilizing the flow pressure generated by circulation or flow of the supply liquid, or by utilizing positive pressure of a gas. The liquid flow pressure can be generated by, for example, a method of actively applying liquid flow pressure using a pump (such as a liquid feed pump or a circulation pump). Examples of the pump include a rotary pump, a diaphragm pump, a metering pump, a chemical pump, a plunger pump, a bellows pump, a gear pump, a vacuum pump, an air pump, and a liquid pump. When circulating or sending the supply liquid by means of a pump, the pump is usually disposed between the supply liquid tank (or circulation tank) and the porous polyimide resin membrane.

[0143] The flow pressure may be, for example, the pressure applied to the polyimide-based resin porous membrane by the supply liquid when the supply liquid is passed through the polyimide-based resin porous membrane by gravity alone, but it is preferable that the flow pressure is applied by the above-mentioned active flow pressure application method. The gas used for pressurization is preferably a gas that is inert or non-reactive with the feed liquid, and specific examples thereof include nitrogen, or rare gases such as helium and argon. A method for applying pressure to the supply liquid side is preferably to use positive gas pressure. In this case, the filtrate side that has passed through the polyimide-based resin porous membrane may be at atmospheric pressure without being reduced pressure.

[0144] The pressurization may be achieved by using both the flow liquid pressure and the positive gas pressure. The differential pressure may be achieved by combining pressurization and decompression, for example, by using both the flow liquid pressure and decompression, by using both the positive gas pressure and decompression, or by using the flow liquid pressure, the positive gas pressure, and decompression. When combining methods for providing a differential pressure, the combination of the flow liquid pressure and the positive gas pressure, or the combination of the flow liquid pressure and decompression is preferred in terms of simplification of production, etc. In this embodiment, since a polyimide-based resin porous membrane is used, even if the pressure difference is provided by a single method such as positive pressure using gas, the foreign matter removal performance is excellent.

[0145] The pressure reduction is achieved by reducing the pressure on the filtrate side that has passed through the polyimide-based resin porous membrane. For example, the pressure reduction may be achieved by a pump, but it is preferable to reduce the pressure to a vacuum.

[0146] When the operation of passing the resist composition through the filter is performed under a pressure difference, the pressure difference is appropriately set in consideration of the film thickness, porosity or average pore size of the polyimide resin porous membrane used, or the desired degree of purification, flow rate, flow velocity, or the concentration or viscosity of the supply liquid, etc. For example, in the case of the so-called cross-flow method (where the supply liquid flows parallel to the polyimide resin porous membrane), the pressure difference is preferably, for example, 0.3 MPa or less. In the case of the so-called dead-end method (wherein the supply liquid is passed across the polyimide-based resin porous membrane), the pressure difference is, for example, preferably 1 MPa or less, more preferably 0.3 MPa or less. The lower limit of each pressure difference is preferably 0.01 MPa or more, more preferably 0.05 MPa or more.

[0147] In the step (i), the operation of passing the resist composition through the filter equipped with the aforementioned polyimide-based resin porous membrane can be carried out in a state in which the flow rate of the resist composition (supply liquid) is maintained high. In this case, the flow rate is not particularly limited, but for example, the flow rate of pure water when pressurized at 0.08 MPa at room temperature (20° C.) is preferably 1 mL / min or more, more preferably 3 mL / min or more, even more preferably 5 mL / min or more, and particularly preferably 10 mL / min or more. The upper limit of the flow rate is not particularly limited, and is, for example, 50 mL / min or less. In this embodiment, since a filter having the above-mentioned polyimide-based resin porous membrane is used, it is possible to perform filtration while maintaining a high flow rate, and thus to increase the removal rate of foreign matter contained in the resist composition.

[0148] Furthermore, in the step (i), the operation of passing the resist composition through a filter is carried out while setting the temperature of the resist composition at 0 to 30°C, and more preferably at 5 to 25°C.

[0149] In step (i), the resist composition may be passed through a filter having a polyimide-based resin porous membrane multiple times (circulation filtration may be performed multiple times), or may be passed through multiple filters including at least a filter having a polyimide-based resin porous membrane.

[0150] <Other processes> The production method according to this embodiment may include other steps in addition to the step (i). Other steps include, for example, a step of contacting the polyimide-based resin porous membrane with a solution of an alcohol such as methanol, ethanol, isopropyl alcohol, or a ketone such as acetone or methyl ethyl ketone, water, a solvent contained in the supply liquid, or a mixture thereof, and passing the liquid through the polyimide-based resin porous membrane in order to wash the polyimide-based resin porous membrane, improve its wettability with respect to the supply liquid, or adjust the surface energy between the polyimide-based resin porous membrane and the supply liquid, before passing the supply liquid through the polyimide-based resin porous membrane. To bring the solution into contact with the polyimide-based resin porous membrane, the polyimide-based resin porous membrane may be impregnated or immersed in the solution. By bringing the solution into contact with the polyimide-based resin porous membrane, for example, the solution can be made to permeate into the pores inside the polyimide-based resin porous membrane. The contact between the solution and the polyimide-based resin porous membrane may be made under the above-mentioned pressure difference, and in particular, when the solution is made to permeate into the pores inside the polyimide-based resin porous membrane, it is preferable to make the contact under pressure.

[0151] ≪Step (ii)≫ The production method according to this embodiment may further include, before the step (i), a step (ii) of cleaning the filter by contacting the filter with a membrane cleaning solution. The membrane cleaning liquid can be used without any particular limitation as long as it can remove organic residues or metal impurities attached to the filter. For example, a preferred membrane cleaning liquid includes a solvent and a metal remover.

[0152] The solvent in the membrane cleaning solution can be appropriately selected from known organic solvents. Specific examples thereof include polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, sulfoxide-based solvents, and sulfone-based solvents; and non-polar solvents such as hydrocarbon-based solvents. Some organic solvents contain multiple types of functional groups in their structure that characterize each solvent, and in such cases, the term "solvent" refers to any type of solvent that contains the functional groups contained in the organic solvent. For example, diethylene glycol monomethyl ether is considered to be either an alcohol solvent or an ether solvent in the above classification. The solvent in the membrane cleaning solution is preferably selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, and ether solvents, and more preferably a mixed solvent of two or more solvents. Note that the two or more solvents may be those that contain at least two compounds and may be two or more solvents of the same classification.

[0153] Examples of the metal remover in the membrane cleaning solution include a metal chelating agent and an organic acid.

[0154] Examples of the metal chelating agent include aminocarboxylic acid chelating agents such as ethylenediaminetetraacetic acid, nitrilotriacetic acid, and diethylenetriaminepentaacetic acid; phosphonic acid chelating agents such as 1-hydroxyethane-1,1-diphosphonic acid and nitrilotris(methylenephosphonic acid); and compound (a1) represented by the following general formula (a-1). Among these, compound (a1) is preferred as the metal chelating agent.

[0155] [ka] [In the formula, Ra 1 and Ra 2 are each independently an alkyl group having 1 to 3 carbon atoms. 3 and Ra 4 are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 1 and Ya2 each independently represents a single bond, -O-, -S- or -N(Ra 5 )-. Ra 5 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. n is an integer of 0 to 3.]

[0156] In the formula (a-1), Ra 1 ~Ra 5 Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, and an isopropyl group. In the formula (a-1), Ra 1 and Ra 2 are each independently preferably a methyl group or an ethyl group, and more preferably a methyl group. Ra 3 and Ra 4 is preferably a hydrogen atom. Ya 1 is preferably a single bond or -O-, and more preferably a single bond. Ya 2 is preferably a single bond or -O-, and more preferably a single bond. n is preferably 1 or 2, and more preferably 1.

[0157] Among the above, compound (a1) is preferably acetylacetone (AcAc) or acetonylacetone, and more preferably acetylacetone (AcAc). In the membrane cleaning solution, the metal chelating agent may be used alone or in combination of two or more kinds.

[0158] Examples of organic acids include carboxylic acids such as lactic acid (LA), citric acid, malic acid, formic acid, acetic acid, oxalic acid, 2-nitrophenylacetic acid, 2-ethylhexanoic acid, and dodecanoic acid; sugar acids such as ascorbic acid and glucuronic acid; sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid; phosphate esters such as bis(2-ethylhexyl)phosphate; and phosphoric acid. Among the above, the organic acid is preferably a carboxylic acid, more preferably a hydroxy acid, and even more preferably at least one selected from the group consisting of lactic acid, citric acid, and malic acid, with lactic acid being particularly preferred. In the membrane cleaning solution, the organic acid may be used alone or in combination of two or more kinds.

[0159] The membrane cleaning solution preferably contains two or more types of metal removers. The membrane cleaning solution preferably contains two or more metal removers selected from the group consisting of the above-mentioned metal chelating agents and organic acids, more preferably contains two or more metal removers selected from the group consisting of the above-mentioned compound (a1) and organic acids, and further preferably contains two or more metal removers selected from the group consisting of the above-mentioned compound (a1) and carboxylic acids.

[0160] Of the above, the membrane cleaning solution preferably uses the above-mentioned metal chelating agent in combination with an organic acid, more preferably uses the above-mentioned compound (a1) in combination with an organic acid, and even more preferably uses the above-mentioned compound (a1) in combination with a carboxylic acid.

[0161] The membrane cleaning solution may contain optional components other than the above-mentioned solvent and metal remover, such as a pH adjuster, a surfactant, etc. A preferred membrane cleaning solution is a membrane cleaning solution containing a solvent and a metal remover, which contains two or more solvents and has a Hansen solubility parameter of 1.0 or less between the membrane cleaning solution and the Hansen solubility parameter of dimethylacetamide (see WO 2022 / 107795).

[0162] The operation of cleaning the filter by contacting the filter with the membrane cleaning solution includes a method of immersing the filter in the membrane cleaning solution and a method of spraying the membrane cleaning solution onto the filter. The cleaning operation may be performed only once or multiple times. Furthermore, during the washing operation, the membrane washing solution may be heated, or the washing operation may be performed at room temperature (for example, 23° C.).

[0163] In addition, as another step, for example, a step of filtering with a filter other than a filter having a polyimide-based resin porous membrane can be mentioned. The filter other than a filter having a polyimide-based resin porous membrane is not particularly limited, but examples thereof include a filter having a thermoplastic resin porous membrane such as a nylon membrane, a polyethylene membrane, a polypropylene membrane, a polytetrafluoroethylene (PTFE) membrane, a tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA) membrane, and a membrane modified therefrom. Among them, it is preferable to use a filter having a porous membrane containing a polyethylene resin as the other filter, since it has excellent foreign matter removal performance.

[0164] ≪Process (iii)≫ The production method according to the present embodiment may be a production method further including, in addition to the step (i), or in addition to the steps (i) and (ii), a step (iii) of filtering through a filter equipped with a porous membrane containing a polyethylene resin. A porous membrane containing polyethylene resin (hereinafter also referred to as "polyethylene resin porous membrane") may consist only of polyethylene resin, or may contain polyethylene resin and other resins, but is preferably composed only of polyethylene resin. The polyethylene resin porous membrane is not particularly limited, and a known one can be used. As the polyethylene resin porous membrane, it is preferable to use a porous membrane of ultra-high molecular weight polyethylene (UPE) because it has excellent impact resistance, abrasion resistance, and chemical resistance. The average pore size of such a porous polyethylene resin membrane is not particularly limited, but from the viewpoint of removing fine foreign matter, it is preferably from 0.1 to 100 nm, more preferably from 0.3 to 50 nm, and even more preferably from 0.5 to 10 nm.

[0165] Examples of filters equipped with such a porous polyethylene resin membrane include filters equipped with a porous polyethylene resin membrane in an outer container made of a thermoplastic resin (polyethylene, polypropylene, PFA, polyethersulfone (PES), polyimide, polyamideimide, etc.).

[0166] The step (iii) is preferably carried out after the step (i). In this case, the average pore size of the polyethylene resin porous membrane is preferably smaller than the average pore size of the communicating pores of the polyimide-based porous membrane. In the manufacturing method of this embodiment, the step (iii) may be repeatedly performed after the step (i). In this case, the resist composition (supply solution) is passed through a filter having a polyimide resin porous membrane and a filter having a polyethylene resin porous membrane while being constantly circulated. When performing the circulation type filtration as described above, it is preferable that both filters are arranged in the circulation path so that the resist composition passes through the filter having a polyimide resin porous membrane and then passes through the filter having a polyethylene resin porous membrane.

[0167] When carrying out step (iii), in the same manner as described in step (i) above, before passing the supply liquid through the polyethylene resin porous membrane, a solution of an alcohol such as methanol, ethanol, isopropyl alcohol, or a ketone such as acetone or methyl ethyl ketone, water, a solvent contained in the supply liquid, or a mixture thereof may be brought into contact with the polyethylene resin porous membrane and passed through the membrane in order to wash the polyethylene resin porous membrane, improve the wettability of the membrane with the supply liquid, or adjust the surface energy between the polyethylene resin porous membrane and the supply liquid.

[0168] <Resist Composition> The resist composition to be filtered generates an acid upon exposure, and the solubility of the resist composition in a developer changes due to the action of the acid. Such a resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes under the action of an acid, and an organic solvent component (S) (hereinafter also referred to as "component (S)"). In the resist composition that is the object to be filtered in this embodiment, component (A) generates an acid upon exposure and contains a resin component (A1) whose solubility in a developer changes under the action of the acid. In addition to component (A1) and component (S), the resist composition may contain other optional components as necessary.

[0169] When a resist film is formed using the resist composition and selectively exposed to light, an acid is generated from the component (A) in the exposed portion of the resist film, and the solubility of the component (A) in the developer changes due to the action of the acid, while the solubility of the component (A) in the developer does not change in the unexposed portion of the resist film, so that a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0170] The resist composition to be filtered may be a positive resist composition or a negative resist composition. The resist composition may be for an alkaline development process using an alkaline developer in the development process when forming a resist pattern, or may be for a solvent development process using a developer containing an organic solvent (organic developer) in the development process.

[0171] ≪Base material component (A)≫ In the resist composition that is the object to be filtered, the component (A) contains a resin component (A1) (hereafter also referred to as “component (A1)”) whose solubility in a developer changes under the action of an acid. By using the component (A1), for example, the polarity of the base component changes before and after exposure, making it possible to obtain good development contrast not only in an alkaline development process but also in a solvent development process. As the component (A), at least one of another polymer compound and a low molecular weight compound may be used in combination with the component (A1). In the resist composition, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0172] About the resin component (A1) The component (A1) is a resin component whose solubility in a developer changes under the action of an acid, and contains a copolymer having a structural unit (a01) having an onium salt structure that generates a sulfonic acid upon exposure, and a structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure. The structural unit (a01) and the structural unit (a02) are both structural units that generate acid upon exposure. In one example of the resist composition, the structural unit (a02) is in a form that traps the acid generated from the structural unit (a01) upon exposure (controls the diffusion of the acid). The component (A1) may contain other structural units, in addition to the structural units (a01) and (a02), as necessary.

[0173] Structural unit (a01) The structural unit (a01) is a structural unit that has an onium salt structure that generates sulfonic acid upon exposure to light. As the structural unit (a01), for example, an anion group (-SO3 - ) on the side chain (anion-bound unit), or a structural unit having a cationic group (onium cation) that decomposes upon exposure on the side chain (cation-bound unit). Of these, the structural unit (a01) is preferably an anion group (-SO3 -In particular, a structural unit having a side chain (anion-bound unit) is preferred.

[0174] Suitable examples of the structural unit (a01) include structural units derived from compounds represented by general formula (a01-b) shown below.

[0175] [ka] [In formula (a01-b), W 01 is a polymerizable group-containing group. 01 R is a divalent linking group or a single bond. 01 and R 02 Each of M is independently a fluorinated alkyl group, a fluorine atom, or a hydrogen atom. m+ is an onium cation having a valence of m, where m is an integer of 1 or more.

[0176] {anion part} In the above formula (a01-b), W 01 Regarding the polymerizable group-containing group in the formula (I), the "polymerizable group" refers to a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and refers to a group that contains a multiple bond between carbon atoms, such as an ethylenic double bond. Examples of the polymerizable group include a vinyl group, an α-methylvinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, a trifluoromethylacryloyl group, a nonylfluorobutylacryloyl group, a vinyl ether group, a fluorine-containing vinyl ether group, an allyl ether group, a fluorine-containing allyl ether group, a styryl group, a vinyl naphthyl group, a fluorine-containing styryl group, a fluorine-containing vinyl naphthyl group, a norbornyl group, a fluorine-containing norbornyl group, a silyl group, and a maleimide group.

[0177] The polymerizable group-containing group may be a group composed only of a polymerizable group, or may be a group composed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Examples of the polymerizable group-containing group include a group represented by the formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 In the above formula, R X11 , R X12 and R X13 each independently represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom; x0 represents a divalent linking group or a single bond.

[0178] R X11 , R X12 and R X13 The alkyl group having 1 to 5 carbon atoms in the formula (I) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R X11 , R X12 and R X13 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. X11 and R X12 is particularly preferably a hydrogen atom, and R X13 is particularly preferably a hydrogen atom or a methyl group.

[0179] Ya x0 Examples of the divalent linking group in the above formula include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.x0 As the divalent linking group, X in the formula (a01-b) described later can be used. 01 Examples of the divalent linking group include the same as those exemplified in the description of the divalent linking group in the above. Preferred examples thereof include an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an ether bond (-O-), a linear or branched alkylene group, an arylene group which may have a substituent, or any combination of these.

[0180] In the formula (a01-b), X 01 In the above formula, examples of the divalent linking group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0181] Optionally substituted divalent hydrocarbon group: X 01 The divalent hydrocarbon group which may have a substituent in the formula (I) may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0182] Aliphatic hydrocarbon groups The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated (for example, an alkenylene group, an alkynylene group, etc.). Examples of the aliphatic hydrocarbon group include a chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, etc. The chain aliphatic hydrocarbon group may be a straight-chain aliphatic hydrocarbon group or a branched-chain aliphatic hydrocarbon group.

[0183] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0184] The linear or branched aliphatic hydrocarbon group may or may not have a substituent.

[0185] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopropane, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0186] The cyclic aliphatic hydrocarbon group may or may not have a substituent, which may be an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or the like. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0187] Aromatic hydrocarbon groups The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0188] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

[0189] Divalent linking groups containing heteroatoms: X 01In the formula (I), examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)- (H may be substituted by a substituent such as a hydrocarbon group, an acyl group, or an alkoxyalkyl group), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as a hydrocarbon group, an acyl group, an alkoxyalkyl group, etc. The substituent preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

[0190] General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as those described above. Y 21 and Y 22 Each of the groups is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, further preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or ethylene group. Or Y 21 and Y 22 Each of the is preferably a linear or branched aliphatic hydrocarbon group, or a linear or branched fluorinated aliphatic hydrocarbon group, and more preferably a linear or branched alkylene group having 1 to 5 carbon atoms, or a linear or branched fluorinated alkylene group.

[0191] X 01 is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), an amide bond [-NH-C(=O)-, -C(=O)-NH-], a linear or branched aliphatic hydrocarbon group, a linear or branched fluorinated aliphatic hydrocarbon group, or a combination of two or more of these, or one which contains a single bond; more preferably a cyclic aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an ester bond [-C(=O)-O-, -OC(=O)-], a linear or branched aliphatic hydrocarbon group, a linear or branched fluorinated aliphatic hydrocarbon group, or one which contains a combination of two or more of these.

[0192] In the above formula (a01-b), R 01 and R 02 are each independently preferably a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a hydrogen atom, preferably a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom, and more preferably a fluorine atom.

[0193] Suitable examples of the structural unit (a01) include structural units represented by general formula (a01-b0) shown below.

[0194] [ka] [In the formula, R m represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 01 represents a divalent linking group or a single bond. 01 represents a hydrocarbon group which may have a substituent. 01 represents a divalent linking group or a single bond. 01 represents a fluorinated alkylene group, an alkylene group, or a single bond. 01 and Va 01 Both of R cannot be single bonds. 00 is a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a hydrogen atom. m+ is an onium cation having a valence of m, where m is an integer of 1 or more.

[0195] In the above formula (a01-b0), R m The alkyl group having 1 to 5 carbon atoms in the formula (I) is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like. R m The halogenated alkyl group having 1 to 5 carbon atoms in the formula (I) is a group in which some or all of the hydrogen atoms in the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is preferable. R m Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R m From the viewpoint of industrial availability, a hydrogen atom or a methyl group is preferred as the alkyl group.

[0196] In the above formula (a01-b0), Yx 01 The divalent linking group in x0 Examples of the divalent linking group include the same divalent linking groups as those exemplified in the description of the divalent linking group in the above. Yx 01 Specific examples of the alkyl group include an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an ether bond (-O-), a linear or branched alkylene group, an arylene group which may have a substituent, or any combination thereof, or a single bond. A combination of an arylene group which may have a substituent and an ester bond (-C(=O)-O-), an ester bond (-C(=O)-O-), or a single bond is preferred, and a combination of a phenylene group which may have a substituent and an ester bond (-C(=O)-O-), or an ester bond (-C(=O)-O-).

[0197] In the above formula (a01-b0), La 01 As for the above, X 01 Examples of the aliphatic hydrocarbon groups include the same ones as those exemplified in the explanation of the divalent hydrocarbon group which may have a substituent in (1) above (a chain-like aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure) and aromatic hydrocarbon groups. Among these, an aliphatic hydrocarbon group containing a ring in the structure and an aromatic hydrocarbon group are preferred, and a cyclic aliphatic hydrocarbon group which may have a substituent (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) and an aromatic hydrocarbon group which may have a substituent are more preferred.

[0198] La 01 The cyclic aliphatic hydrocarbon group in may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group, preferably a polycyclic alicyclic hydrocarbon group, more preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and even more preferably a group in which two hydrogen atoms have been removed from an adamantane. The cyclic aliphatic hydrocarbon group may or may not have a substituent, which may be an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or the like. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0199] La 01 The aromatic hydrocarbon group in is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring or an aromatic heterocycle (an arylene group or a heteroarylene group), more preferably an arylene group, and even more preferably a phenylene group. The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

[0200] Among the above, La 01 is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, and more preferably a polycyclic alicyclic hydrocarbon group which may have a substituent.

[0201] In the above formula (a01-b0), Ya 01 The divalent linking group in 01 Examples of the divalent linking group containing a hetero atom include those similar to the divalent linking group containing a hetero atom in the above formula (I). Ya 01 is preferably an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), or an oxycarbonyl group (-OC(=O)-), and (La 01 side)-C(=O)-O-(Va 01 It is more preferable that the side of the substrate is the side of the substrate.

[0202] In the above formula (a01-b0), Va01 The alkylene group in the formula (I) is the same as that in the formula (I). 01 The linear or branched aliphatic hydrocarbon group in the formula (Va) is the same as that in the formula (Va). 01 The fluorinated alkylene group in 01 In the above formula, some or all of the hydrogen atoms constituting the alkylene group are substituted with fluorine atoms. Va 01 is preferably a methylene group (-CH2-) or -CH(CF3)-.

[0203] In the above formula (a01-b0), R 00 represents a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom or a hydrogen atom, preferably a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom, and more preferably a fluorine atom.

[0204] Specific examples of the structural unit (a01) include, but are not limited to, the following. In each formula, R α represents a trifluoromethyl group, a methyl group, or a hydrogen atom. m+ is an onium cation with a valence of m, where m is an integer of 1 or greater.

[0205] [ka]

[0206] [ka]

[0207] [ka]

[0208] [ka]

[0209] The structural unit (a01) is preferably a structural unit selected from the group consisting of structural units represented by any one of the formulas (a01-b01) to (a01-b05), structural units represented by any one of the formulas (a01-b06) to (a01-b16), and structural units represented by any one of the formulas (a01-b17) to (a01-b23), more preferably a structural unit selected from the group consisting of structural units represented by any one of the formulas (a01-b06) to (a01-b16), and structural units represented by any one of the formulas (a01-b17) to (a01-b23), even more preferably a structural unit selected from the group consisting of structural units represented by any one of the formulas (a01-b06) to (a01-b16), and particularly preferably a structural unit selected from the group consisting of structural units represented by any one of the formulas (a01-b09) to (a01-b16).

[0210] {cationic part} In the above formula (a01-b) and formula (a01-b0), M m+ is an onium cation having a valence of m, where m is an integer of 1 or more. m+ Among the onium cations in the formula (I), sulfonium cations and iodonium cations are preferred, and sulfonium cations are more preferred. Preferred cationic moieties (M m+ ) 1 / m Examples of the onium cation include the onium cations represented by the following general formulas (ca-1) to (ca-3).

[0211] [ka] [In the formula, R 201 ~R 207 R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 L is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-.

[0212] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of the substituent that may be possessed by include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-8), etc. Among these, an alkyl group, a halogen atom, a halogenated alkyl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-8), respectively, are preferred, and a chain alkyl group, an iodine atom, a fluorine atom, a fluorinated alkyl group, and groups represented by the following general formula (ca-r-3) are more preferred.

[0213] [ka] [In the formula, R' 201 are each independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0214] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0215] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring of the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0216] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0217] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0218] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0219] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) described below, -SO2--containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) described below, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) below.

[0220] [ka]

[0221] R' 201 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom or an iodine atom is preferred. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0222] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and most preferably has 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably has 3 to 15 carbon atoms, and most preferably has 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0223] An optionally substituted chain alkenyl group: R' 201The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, further preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0224] R' 201 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above R' 201 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0225] R' 201 In addition to the above-mentioned, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) described later as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0226] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7) described below, and an -SO2--containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) described below are preferred. For example, from the standpoint of achieving high sensitivity when forming a resist pattern, the compound is preferably an aromatic hydrocarbon group which may have a substituent, more preferably an aromatic hydrocarbon group having an iodine atom bonded to it as a substituent, and particularly preferably a benzene ring having an iodine atom bonded to it as a substituent.

[0227] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, in which a ring containing a sulfur atom in the ring skeleton in the formula is a 3- to 10-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0228] R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups they may be bonded to each other to form a ring.

[0229] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 In the above, the -SO2- containing cyclic group is not particularly limited and any group can be used. Specifically, the groups represented by the following general formulae (b5-r-1) to (b5-r-4) can be mentioned, with the "-SO2- containing polycyclic group" being preferred, and the group represented by the general formula (b5-r-1) being more preferred.

[0230] [ka] [In the formula, Rb' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group or a -SO2- containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.]

[0231] In the general formulas (b5-r-1) and (b5-r-2), B" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom. B" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably a methylene group.

[0232] In the general formulae (b5-r-1) to (b5-r-4), Rb' 51are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group, and among these, they are preferably each independently a hydrogen atom or a cyano group.

[0233] Specific examples of the groups represented by general formulas (b5-r-1) to (b5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0238] [ka]

[0239] [ka]

[0240] [ka] [In the formula, g1, g2, and g3 each represent a repeating number, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0241] [ka]

[0242] [ka]

[0243] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the above-mentioned R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the

[0244] [ka]

[0245] [ka]

[0246] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0247] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0248] [ka]

[0249] The cation moiety ((M m+ ) 1 / m), the cations represented by the formulas (ca-1) to (ca-3) are more preferable, and the cations represented by the formulas (ca-1-1) to (ca-1-87) are particularly preferable; the diphenyliodonium cation and the bis(4-tert-butylphenyl)iodonium cation are particularly preferable. Among these, the cation represented by the formula (ca-1) is preferred, and particularly from the viewpoint of increasing sensitivity, the suitable cation represented by the formula (ca-1) is preferably one having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, a sulfonyl group, or the like; or an iodine atom as a substituent, and for example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84), and (ca-1-85) to (ca-1-87) is particularly preferred. The number of the substituents is, for example, 1 to 4, 1 to 3, 2 or 1.

[0250] Specific examples of the structural unit (a01) include, but are not limited to, the following. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0251] [ka]

[0252] The structural unit (a01) is preferably a structural unit selected from the group consisting of structural units represented by any one of the above formulas (a01-b-1) to (a01-b-4).

[0253] The structural unit (a01) contained in the component (A1) may be of one type, or two or more types. The proportion of the structural unit (a01) in the component (A1) is preferably from 1 to 40 mol %, more preferably from 2 to 30 mol %, even more preferably from 5 to 25 mol %, and particularly preferably from 10 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a01) is at least the lower limit of the above-mentioned preferred range, the sensitivity during resist pattern formation is improved, and lithography properties such as reduced pattern roughness are easily improved. When the proportion of the structural unit (a01) is at most the upper limit of the above-mentioned preferred range, it is easy to achieve a balance with other structural units.

[0254] Structural unit (a02) The structural unit (a02) is a structural unit that has an onium salt structure that generates a carboxylic acid upon exposure to light. Examples of the structural unit (a02) include an anion group (-COO - ) on the side chain (anion-bound unit), or a structural unit having a cationic group (onium cation) that decomposes upon exposure on the side chain (cation-bound unit). Of these, the structural unit (a02) is preferably an anion group (-COO - In particular, a structural unit having a side chain (anion-bound unit) is preferred.

[0255] Suitable examples of the structural unit (a02) include structural units derived from compounds represented by general formula (a02-d) shown below.

[0256] [ka] [In formula (a02-d), W 02 is a polymerizable group-containing group. 02 is a divalent linking group or a single bond. n+ is an onium cation having a valency of n, where n is an integer of 1 or more.

[0257] {anion part} In the above formula (a02-d), W 02 The polymerizable group-containing group in the above formula (a01-b) is 01This is the same as the explanation for the polymerizable group-containing group in the above. W 02 As the polymerizable group-containing group in the formula: X11 )(R X12 )=C(R X13 )-Ya x0 In the above formula, R X11 , R X12 and R X13 each independently represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom; x0 represents a divalent linking group or a single bond. R X11 , R X12 and R X13 is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. X11 and R X12 is particularly preferably a hydrogen atom, and R X13 is particularly preferably a hydrogen atom or a methyl group. Ya x0 Examples of the alkyl group include a single bond, an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an ether bond (-O-), a linear or branched alkylene group, an arylene group which may have a substituent, or any combination thereof.

[0258] In the formula (a02-d), X 02 In the above formula, examples of the divalent linking group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. X 02 The divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the above formula (a01-b) are 01 The explanations for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the above are the same as those for the divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in the above. X 02is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), an amide bond [-NH-C(=O)-, -C(=O)-NH-], a linear or branched aliphatic hydrocarbon group, or a combination of two or more of these, or one which contains a single bond; more preferably an aromatic hydrocarbon group which may have a substituent, an ether bond (-O-), a linear or branched aliphatic hydrocarbon group, or one which contains a combination of two or more of these.

[0259] Suitable examples of the structural unit (a02) include structural units represented by general formula (a02-d0) shown below.

[0260] [ka] [In the formula, R m represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 02 represents a divalent linking group or a single bond. 02 represents a hydrocarbon group which may have a substituent. 02 represents a divalent linking group or a single bond. n+ is an onium cation having a valency of n, where n is an integer of 1 or more.

[0261] In the above formula (a02-d0), R m R in the above formula (a01-b0) m The explanation is the same as for R. m From the viewpoint of industrial availability, a hydrogen atom or a methyl group is preferred as the alkyl group.

[0262] In the above formula (a02-d0), Yx 02 is Yx in the formula (a01-b0). 01 The explanation is the same as for Yx 02Specific examples of the above include an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an ether bond (-O-), a linear or branched alkylene group, an arylene group which may have a substituent, or any combination thereof, or a single bond. A combination of an arylene group which may have a substituent, a linear or branched alkylene group and an ether bond (-O-), an ester bond (-C(=O)-O-), or a single bond is preferred.

[0263] In the above formula (a02-d0), La 02 represents La in the above formula (a01-b0). 01 The same applies as the description of the optionally substituted hydrocarbon group in the above. La 02 As for the above, X 01 Examples of the aliphatic hydrocarbon groups include the same aliphatic hydrocarbon groups (chain-like aliphatic hydrocarbon groups and aliphatic hydrocarbon groups containing a ring in the structure) and aromatic hydrocarbon groups as exemplified in the description of the divalent hydrocarbon groups which may have a substituent in (1), and an aliphatic hydrocarbon group or aromatic hydrocarbon group which contains a ring in the structure is preferred, and a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may have a substituent, and an aromatic hydrocarbon group which may have a substituent are more preferred.

[0264] La 02 The cyclic aliphatic hydrocarbon group in may be a monocyclic alicyclic hydrocarbon group or a polycyclic alicyclic hydrocarbon group, preferably a polycyclic alicyclic hydrocarbon group, more preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and even more preferably a group in which two hydrogen atoms have been removed from an adamantane. The cyclic aliphatic hydrocarbon group may or may not have a substituent, which may be an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, or the like. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0265] La 02 The aromatic hydrocarbon group in is preferably a group in which two hydrogen atoms have been removed from an aromatic hydrocarbon ring or an aromatic heterocycle (an arylene group or a heteroarylene group), more preferably an arylene group, and even more preferably a phenylene group. The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

[0266] Among the above, La 02 is preferably an aromatic hydrocarbon group which may have a substituent, and more preferably an arylene group which may have a substituent. La 02 From the viewpoint of solubility in a developer, the substituent that the aromatic hydrocarbon group may have in the above formula (1) is preferably a hydroxy group. The number of hydroxy groups as the substituents may be, for example, 2 or 1. Also, La 02 The substituent that the aromatic hydrocarbon group may have in the above is preferably a halogen atom or a hydroxyl group. From the viewpoint of increasing sensitivity when forming a resist pattern, a halogen atom is more preferable, and an iodine atom is even more preferable. The number of iodine atoms as the substituent may be, for example, 1 to 4, 1 to 3, 2, or 1. The greater the number of iodine atoms as the substituent, the easier it is to increase sensitivity. In addition, due to the effect of the iodine atom, pattern bridging is reduced in areas with a low exposure dose, and pattern collapse is reduced in areas with a high exposure dose, which makes it easier to expand the process margin.

[0267] In the above formula (a02-d0), Ya 02 In the above, the divalent linking group is X in the formula (a01-b). 01 The heteroatom-containing divalent linking group in the above formula (I) is the same as that in the above formula (I). 02 represents an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), a linear or branched alkylene group, any combination thereof, or a single bond, and is preferably a single bond.

[0268] Specific examples of the structural unit (a02) include, but are not limited to, the following. In each formula, R α represents a trifluoromethyl group, a methyl group, or a hydrogen atom. n+ is an onium cation having a valence of n, where n is an integer of 1 or more.

[0269] [ka]

[0270] A structural unit selected from the group consisting of structural units represented by any of the above formulas (a02-d01) to (a02-d08) is preferred, and a structural unit selected from the group consisting of structural units represented by any of the above formulas (a02-d01) to (a02-d04) is more preferred.

[0271] {cationic part} In the above formula (a02-d) and formula (a02-d0), N n+ is an onium cation having a valence of n, where n is an integer of 1 or more. n+ Among the onium cations in the formula (I), sulfonium cations and iodonium cations are preferred, and sulfonium cations are more preferred. The preferred cationic moiety (N n+ ) 1 / nExamples of the onium cations include those represented by the above general formulas (ca-1) to (ca-3), and among these, the cations represented by the above formulas (ca-1-1) to (ca-1-87), respectively; diphenyliodonium cation, and bis(4-tert-butylphenyl)iodonium cation are more preferred. Among these, the cation represented by the formula (ca-1) is preferred, and particularly from the viewpoint of increasing sensitivity, the suitable cation represented by the formula (ca-1) is preferably one having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, a sulfonyl group, or an iodine atom as a substituent, and for example, a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84), and (ca-1-85) to (ca-1-87) is particularly preferred. The number of the substituents is, for example, 1 to 4, 1 to 3, 2 or 1.

[0272] Specific examples of the structural unit (a02) include, but are not limited to, the following. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0273] [ka]

[0274] The structural unit (a02) is preferably a structural unit selected from the group consisting of structural units represented by any of the above formulae (a02-d-1) to (a02-d-4).

[0275] The structural unit (a02) contained in the component (A1) may be of one type, or two or more types. The proportion of the structural unit (a02) in the component (A1) is preferably 0.5 to 20 mol %, more preferably 1 to 15 mol %, even more preferably 1 to 10 mol %, and particularly preferably 2 to 8 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a02) is at least as large as the lower limit of the aforementioned preferred range, it becomes easier to improve lithography properties such as reducing pattern roughness, etc. When the proportion of the structural unit (a02) is at most the upper limit of the aforementioned preferred range, it becomes easier to achieve a balance with other structural units.

[0276] Other structural units The component (A1) may contain other structural units, in addition to the above-mentioned structural units (a01) and (a02), as necessary. Examples of other structural units include a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid; a structural unit (a10) represented by general formula (a10-1) described below; a structural unit (a2) containing a lactone-containing cyclic group; and a structural unit (a8) derived from a compound represented by general formula (a8-1) described below.

[0277] Structural unit (a1): The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid. Examples of the acid dissociable group that constitutes the acid decomposable group include those that have been proposed as acid dissociable groups in base resins for chemically amplified resist compositions. Examples of acid dissociable groups that have been proposed for use in base resins for chemically amplified resist compositions include “acetal-type acid dissociable groups,” “tertiary alkyl ester-type acid dissociable groups,” “tertiary alkyloxycarbonyl acid dissociable groups,” and “secondary alkyl ester-type acid dissociable groups.”

[0278] Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0279] [ka] [In the formula, Ra' 1 , Ra'2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0280] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 Or Ra' 2 When is an alkyl group, the alkyl group may be the same as the alkyl group exemplified as the substituent that may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are preferable, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0281] In formula (a1-r-1), Ra' 3 Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0282] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0283] Ra' 3 When is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0284] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ra'3 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0285] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra x5 " Also known as ".) Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0286] Ra' 3 But Ra' 1 , Ra' 2 When it is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, etc.

[0287] Tertiary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for the sake of convenience.

[0288] [ka] [In the formula, Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0289] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, a linear alkynyl group, or a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the alicyclic hydrocarbon group which is a monocyclic group, the alicyclic hydrocarbon group which is a polycyclic group, and the aromatic hydrocarbon group) in the formula Ra' 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The same can be mentioned.

[0290] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably used. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0291] [ka] [In formula (a1-r2-1), Ra' 10 Ra' represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. 11 Is Ra' 10 In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond (hereinafter the same).

[0292] In the above formula (a1-r2-1), Ra' 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0293] Ra' 10In the formula, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In the above, the branched alkyl group is 3 The same can be mentioned.

[0294] Ra' 10 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. In addition, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatom includes an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0295] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which is bonded) is Ra' in formula (a1-r-1). 3 Among them, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0296] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 Examples of such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (alicyclic hydrocarbon group) in the above formula. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' 3Examples of the substituents include those similar to those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra 103 In the above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0297] The above Ra 101 ~Ra 103 Examples of the substituents of the chain saturated hydrocarbon group or the cyclic saturated aliphatic hydrocarbon group represented by the formula x5 The same groups as those shown below can be mentioned.

[0298] Ra 101 ~Ra 103Examples of groups containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0299] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is represented by Ra' in formula (a1-r-1). 3 The groups mentioned above as the alicyclic hydrocarbon group are preferably monocyclic or polycyclic groups of the above formula. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 104 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0300] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0301] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of Ra' is independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13In the above, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is 101 ~Ra 103 Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above formula are the same as those in the above formula. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group or an ethyl group is further preferable, and a methyl group is particularly preferable. The above Ra' 12 and Ra' 13 In the case where the chain saturated hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0302] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0303] Ra' 14 The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0304] Ra' 14 The branched alkyl group in the above formula (I) preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0305] Ra'14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0306] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon group Ra' is the same as that in 14 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 104 The substituents may be the same as those which may be possessed by the group.

[0307] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0308] Specific examples of the group represented by formula (a1-r2-1) are shown below.

[0309] [ka]

[0310] [ka]

[0311] [ka]

[0312] Specific examples of the group represented by formula (a1-r2-2) are shown below.

[0313] [ka]

[0314] [ka]

[0315] [ka]

[0316] Specific examples of the group represented by formula (a1-r2-3) are shown below.

[0317] [ka]

[0318] Specific examples of the group represented by formula (a1-r2-4) are shown below.

[0319] [ka]

[0320] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid dissociable group that protects the hydroxyl group include acid dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid dissociable group").

[0321] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0322] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of the groups is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0323] Secondary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-4).

[0324] [ka] [In the formula, Ra' 10 is a hydrocarbon group. 11a and Ra' 11b Each of Ra' independently represents a hydrogen atom, a halogen atom, or an alkyl group. 12is a hydrogen atom or a hydrocarbon group. 10 and Ra' 11a Or Ra' 11b and may be bonded to each other to form a ring. 11a Or Ra' 11b And, Ra' 12 may be bonded to each other to form a ring.

[0325] In the formula, Ra' 10 and Ra' 12 As the hydrocarbon group in Ra', 3 The same can be mentioned. In the formula, Ra' 11a and Ra' 11b As the alkyl group in the above, Ra' 1 The alkyl groups in the above formula (I) are the same as those in the above formula (I). In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in 11a and Ra' 11b The alkyl group in may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0326] Ra' 10 and Ra' 11a Or Ra' 11b may be bonded to each other to form a ring. The ring may be a polycyclic ring or a monocyclic ring, an alicyclic ring, or an aromatic ring. The alicyclic and aromatic rings may contain heteroatoms.

[0327] Ra' 10 and Ra' 11a Or Ra' 11b and are bonded to each other to form a ring. Among the above, preferred are monocycloalkenes, rings in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), and monocycloalkadiene, more preferred are cycloalkenes having 3 to 6 carbon atoms, and more preferred are cyclopentene or cyclohexene.

[0328] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by bonding with each other may be a condensed ring. Specific examples of the condensed ring include indan.

[0329] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by bonding with each other may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0330] Ra' 11a Or Ra' 11b And, Ra' 12 and may be bonded to each other to form a ring, and the ring may include Ra' 10 and Ra' 11a Or Ra' 11b and the like are similar to the ring formed by bonding with each other.

[0331] Specific examples of the group represented by formula (a1-r-4) are shown below.

[0332] [ka]

[0333] Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a structural unit derived from an acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl groups are protected with a substituent containing the above-mentioned acid-decomposable group, and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a portion of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0334] Of the above, the structural unit (a1) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1), general formula (a1-2) or general formula (a1-3).

[0335] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 is an acid-dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). 1 is a2 +1 valent hydrocarbon group. n a2 is an integer from 1 to 3. 2 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3). 001 is a single bond or a divalent linking group. 1 is a single bond or a divalent linking group. 01 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). q is an integer of 0 to 3. n is an integer of 1 or more, provided that n≦q×2+4.]

[0336] In the formulas (a1-1) to (a1-3), the alkyl group of R having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

[0337] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0338] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0339] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0340] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically cycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0341] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0342] In the formula (a1-1), Ra 1 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, a group represented by general formula (a1-r2-1) or an acid dissociable group represented by general formula (a1-r-4) is more preferable.

[0343] In the formula (a1-2), Wa 1 n in a2 The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that combines a straight-chain or branched-chain aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in its structure. The above n a2 The +1 valency is preferably 2 to 4, more preferably 2 or 3. In the formula (a1-2), Ra 2 is preferably an acid dissociable group represented by the above general formula (a1-r-1).

[0344] In the formula (a1-3), Ya 001 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 001 is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. Among these, Ya 001is preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0345] In the formula (a1-3), Ya 1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 1 Among the above, Ya is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. 1 is preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0346] In the formula (a1-3), Rax 01 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, an acid dissociable group represented by general formula (a1-r-2) is more preferable, and a group represented by general formula (a1-r2-1) is even more preferable.

[0347] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, the structure is a benzene structure, when q is 1, the structure is a naphthalene structure, when q is 2, the structure is an anthracene structure, and when q is 3, the structure is a tetracene structure. In the above formula (a1-3), n is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. In the formula (a1-3), n≦q×2+4. For example, when q is 1 and the naphthalene structure is a naphthalene structure, all six hydrogen atoms of the naphthalene may be substituted with hydroxy groups. 001 , -Ya 1 -C(=O)-O-Rax01 The substitution positions of the group and the hydroxy group are not particularly limited.

[0348] Specific examples of the structural unit (a1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0349] [ka]

[0350] [ka]

[0351] [ka]

[0352] [ka]

[0353] [ka]

[0354] [ka]

[0355] [ka]

[0356] [ka]

[0357] [ka]

[0358] [ka]

[0359] [ka]

[0360] [ka]

[0361] [ka]

[0362] [ka]

[0363] The structural unit (a1) contained in the component (A1) may be of one type, or two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) or a structural unit represented by the above formula (a1-3) is more preferable, since these structural units are capable of more easily improving the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography. Among these, the acid dissociable group (Ra 1 , Rax 01 ) are preferably acid-dissociable groups represented by the following general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), respectively, and among these, it is particularly preferable to select those which are cyclic groups.

[0364] [ka] [In the formula, Ra 1" is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4). * represents a bond.

[0365] In the formula (a1-1-1), R and Va 1 and n a1 R and Va in the formula (a1-1) 1 and n a1 is the same as: The acid dissociable group represented by formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4) is as described above. Among them, it is preferable to select the acid dissociable group as a cyclic group, since it is suitable for EB or EUV use in that reactivity can be increased.

[0366] The proportion of the structural unit (a1) in the component (A1) is preferably 20 to 75 mol %, more preferably 25 to 70 mol %, even more preferably 30 to 60 mol %, and particularly preferably 35 to 55 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By making the proportion of the structural unit (a1) equal to or greater than the lower limit of the preferred range, it becomes easier to achieve high sensitivity and etching resistance, and it becomes easier to improve roughness and exposure latitude. On the other hand, by making the proportion equal to or less than the upper limit of the preferred range, it becomes possible to achieve a good balance with other structural units, and various lithography properties become good.

[0367] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by general formula (a10-1) shown below.

[0368] [ka] In formula (a10-1), R represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. x1 is a divalent linking group or a single bond. x1 is an aromatic hydrocarbon group which may have a substituent.ax1 represents an integer equal to or greater than 1, as permitted by atomic valence.

[0369] In the formula (a10-1), R is the same as R in the general formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0370] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0371] Optionally substituted divalent hydrocarbon group: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0372] Aliphatic hydrocarbon groups The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0373] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0374] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0375] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0376] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0377] Aromatic hydrocarbon groups The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0378] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0379] Divalent linking groups containing heteroatoms: Examples of the divalent linking group containing a hetero atom include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as those described above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0380] Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0381] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax14n+1) hydrogen atoms are removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0382] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include Ya x1 The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0383] In the formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0384] Specific examples of the structural unit (a10) represented by the aforementioned formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0385] [ka]

[0386] [ka]

[0387] [ka]

[0388] The structural unit (a10) that the component (A1) can have may be of one type, or two or more types. The component (A1) may or may not contain the structural unit (a10), but it preferably contains the structural unit (a10). When the component (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is preferably 10 to 60 mol %, more preferably 20 to 50 mol %, even more preferably 25 to 45 mol %, and particularly preferably 30 to 40 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, it is possible to further increase the sensitivity, whereas by ensuring that the proportion is at most the upper limit of the above range, it is easier to achieve a balance with other structural units.

[0389] Regarding the structural unit (a2): The component (A1) may further include a structural unit (a2) that includes a lactone-containing cyclic group (provided that this does not fall under the category of the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when the (A1) component is used to form a resist film. In addition, the structural unit (a2) has the effects of, for example, appropriately adjusting the acid diffusion length, increasing the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development, thereby improving the lithography properties, etc.

[0390] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include the groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0391] [ka] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group or a lactone-containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond (the same applies hereinafter).]

[0392] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. 21 Examples of the alkyl group include those groups in which the alkyl groups mentioned above are linked to an oxygen atom (-O-). Ra' 21 As the halogen atom in, a fluorine atom is preferable. Ra' 21 As the halogenated alkyl group in the above, Ra' 21 and groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the above-mentioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0393] Ra' 21 In -COOR" and -OC(=O)R", R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Ra' 21 The hydroxyalkyl group in Ra' is preferably one having 1 to 6 carbon atoms. 21 In the above formula, at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0394] Ra' 21 Among the above, it is preferable that each of them independently is a hydrogen atom or a cyano group.

[0395] In the general formulae (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the carbon atoms of the alkylene group, and examples thereof include -O-CH2-, -CH2-O-CH2-, -S-CH2- and -CH2-S-CH2-. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0396] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0397] [ka]

[0398] [ka]

[0399] Of the various possibilities, the structural unit (a2) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0400] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 21 is a single bond or a divalent linking group. 21is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group.

[0401] In the formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0402] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 21 As the divalent linking group, Ya in the above general formula (a10-1) is x1 The divalent linking group may be the same as the divalent linking group in the above formula.

[0403] Ya 21 is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0404] In the formula (a2-1), Ya 21 is a single bond, La 21 is preferably -COO- or -OCO-.

[0405] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group. Ra 21 Suitable examples of the lactone-containing cyclic group in include the groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), respectively.

[0406] The structural unit (a2) that the component (A1) can have may be of one type, or two or more types. The component (A1) may or may not contain the structural unit (a2). When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 5 to 15 mol %. When the proportion of the structural unit (a2) is at least as large as the preferred lower limit, the effects achieved by including the structural unit (a2) as described above can be fully obtained. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0407] Regarding the structural unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by general formula (a8-1) shown below.

[0408] [ka] [In the formula, W 2 is a polymerizable group-containing group. x2 is a single bond or (n ax2 +1)valent linking group. x2 and W 2 R may form a condensed ring. 1 R is a fluorinated alkyl group having 1 to 12 carbon atoms. 2 R is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. 2 and Ya x2 may be bonded to each other to form a ring structure. ax2 is an integer from 1 to 3.

[0409] In the formula (a8-1), W 2 The polymerizable group-containing group in the above formula (a01-b) is 01 This is the same as the explanation for the polymerizable group-containing group in the above. W2 As the polymerizable group-containing group in the formula: X11 )(R X12 )=C(R X13 )-Ya x0 A preferred example is a group represented by the formula: In this chemical formula, R X11 , R X12 and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; x0 is a single bond or a divalent linking group.

[0410] Ya x2 and W 2 The condensed ring formed by 2 Polymerizable group of the site and Ya x2 and W 2 Other groups than the polymerizable group at the Ya site x2 and Ya x2 and W 2 The condensed ring formed by these may have a substituent.

[0411] Specific examples of the structural unit (a8) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0412] [ka]

[0413] Among the above examples, the structural unit (a8) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0414] The structural unit (a8) that the component (A1) can have may be of one type, or two or more types. The component (A1) may or may not contain the structural unit (a8). When the component (A1) contains the structural unit (a8), the proportion of the structural unit (a8) in the component (A1) is preferably 30 mol % or less, more preferably 0 to 20 mol %, and even more preferably 0 to 10 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1).

[0415] The component (A1) that the resist composition contains as a base component may use either a single type of compound, or a combination of two or more types of compounds.

[0416] In the resist composition to be filtered, the component (A1) contains a copolymer having the above-mentioned structural units (a01) and (a02), preferably a copolymer having the above-mentioned structural units (a01), (a02), and (a1), more preferably a copolymer having the above-mentioned structural units (a01), (a02), (a1), and (a10), and particularly preferably a copolymer consisting of the above-mentioned structural units (a01), (a02), (a1), and (a10).

[0417] In a copolymer having the structural unit (a01), the structural unit (a02), the structural unit (a1), and the structural unit (a10), the proportion of the structural unit (a01) relative to the total (100 mol%) of all structural units constituting the copolymer is preferably 2 to 30 mol%, more preferably 5 to 25 mol%, and even more preferably 10 to 20 mol%; the proportion of the structural unit (a02) relative to the total (100 mol%) of all structural units constituting the copolymer is preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%. %, more preferably 2 to 8 mol %; the proportion of the structural unit (a1) relative to the total (100 mol %) of all structural units constituting the copolymer is preferably 25 to 70 mol %, more preferably 30 to 60 mol %, and even more preferably 35 to 55 mol %; and the proportion of the structural unit (a10) relative to the total (100 mol %) of all structural units constituting the copolymer is preferably 20 to 50 mol %, more preferably 25 to 45 mol %, and even more preferably 30 to 40 mol %. However, the total amount of the structural units (a01), (a02), (a1) and (a10) does not exceed 100 mol %.

[0418] The total proportion of the structural units (a01) and the structural units (a02) relative to the total (100 mol%) of all structural units constituting the copolymer is preferably 5 to 40 mol%, more preferably 10 to 30 mol%, and even more preferably 15 to 25 mol%.

[0419] The ratio of the structural units (a01) to the structural units (a02), expressed as the molar ratio structural unit (a01) / structural unit (a02), is preferably from 60 / 40 to 90 / 10, more preferably from 65 / 35 to 85 / 15, and even more preferably from 70 / 30 to 80 / 20. When the molar ratio is at least the lower limit of the above-mentioned preferred range, the sensitivity when forming a resist pattern is further improved, whereas when the molar ratio is at most the upper limit of the above-mentioned preferred range, the lithography properties such as reduced pattern roughness are further improved.

[0420] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of the component (A1) is no more than the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is no less than the preferred lower limit of this range, the dry etching resistance and cross-sectional shape of the resist pattern are excellent. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0421] Regarding component (A2) The resist composition to be filtered may use, in combination with the component (A), a base component (hereafter referred to as “component (A2)”) that does not fall under the category of the component (A1) and whose solubility in a developer changes due to the action of an acid. There are no particular restrictions on the component (A2), and it may be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more.

[0422] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, and even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of the (A) component. When the proportion is 25% by mass or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and reduced roughness is easily formed, and in addition, the process margin is also easily expanded.

[0423] The amount of the component (A) in the resist composition may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0424] <Organic solvent component (S)> The resist composition to be filtered contains an organic solvent component (hereafter referred to as “component (S)”). Such a resist composition is produced by dissolving a resist material in component (S). The component (S) can be any solvent that is capable of dissolving the individual components used to form a homogeneous solution, and any solvent can be appropriately selected from those known in the art as a solvent for chemically amplified resist compositions. In the resist composition, the component (S) may be used alone or as a mixed solvent of two or more kinds. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0425] As the component (S), a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. As the component (S), a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone is also preferred. In this case, the mixing ratio of the former to the latter is preferably 70:30 to 95:5 by mass. The amount of the component (S) used is not particularly limited, and is set appropriately depending on the coating film thickness at a concentration that allows application to a substrate, etc. In general, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0426] <Other ingredients> The resist composition to be filtered may further contain other components in addition to the above-mentioned component (A), such as the following components (B), (D), (E), and (F).

[0427] Acid generator component (B) The resist composition to be filtered may further contain an acid generator component (B) (component (B)) that generates acid upon exposure to light. There are no particular limitations on the component (B), and any of the compounds that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0428] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0429] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0430] [ka] [In the formula, R 101 and R 104 ~R 108 R each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 and R 105 R may be bonded to each other to form a ring structure. 102 Y is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 and V 101 cannot be a single bond at the same time. 101 ~L 102 Each of L is independently a single bond or an oxygen atom. 103 ~L 105 are each independently a single bond, -CO- or -SO2-. m is an integer of 1 or more, and M' m+ is an onium cation with a valence of m.

[0431] {anion part} Anion in component (b-1) In formula (b-1), R 101 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0432] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. In addition, the aliphatic hydrocarbon group is preferably saturated.

[0433] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring of the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, etc.), etc. The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0434] R 101 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0435] Among them, R 101The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0436] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0437] Also, R 101The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the above general formulae (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the above general formulae (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the above chemical formulae (r-hr-1) to (r-hr-16). * in the formula represents Y in formula (b-1). 101 Represents a bond that bonds to .

[0438] R 101 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom, a bromine atom or an iodine atom is preferred. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0439] R 101The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following formulas (r-br-1) to (r-br-2). 101 Represents a bond that bonds to .

[0440] [ka]

[0441] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused ring group are defined as R 101 Examples of the substituents of the cyclic group in the above formula (I) include the same as those exemplified as the substituents of the cyclic group in the above formula (I). Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and the heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; groups obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; -SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0442] A chain alkyl group which may have a substituent: R 101 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0443] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0444] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0445] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7). In the following general formulas (y-al-1) to (y-al-7), R 101 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 It is.

[0446] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0447] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0448] V'101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 In the above formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the above formula (a1-r-1). 3 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0449] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0450] In formula (b-1), R 102R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0451] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulas (an-1) to (an-3).

[0452] [ka] [In the formula, R” 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an -SO2- containing cyclic group represented by each of the above general formulas (b5-r-1) to (b5-r-4). 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0453] R” 101 , R.” 102 and R.” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 As the substituent, R in the formula (b-1) is preferably a group exemplified as the cyclic aliphatic hydrocarbon group. 101 Examples of the substituents which may substitute the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0454] R” 101 and R.” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 The substituents which may substitute the aromatic hydrocarbon group in the above formula (I) are the same as those in the above formula (I).

[0455] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula (I). R” 103 The chain alkenyl group which may have a substituent is represented by R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0456] Anion in component (b-2) In formula (b-2), R 104 , R 105 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each represents R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105is preferably a chain alkyl group which may have a substituent, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain-like alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in a resist solvent. 104 , R 105 In the chain alkyl group, the more hydrogen atoms substituted with fluorine atoms, the stronger the acid strength becomes, and the more the transparency to high-energy light of 250 nm or less and electron beams improves, which is preferable. The ratio of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0457] Anion in component (b-3) In formula (b-3), R 106 ~R 108 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each represents R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0458] Among the above, the anion moiety of the component (B) is preferably the anion in the component (b-1), and more preferably the anion represented by the above formula (an-1).

[0459] {cationic part} In the above formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an onium cation having a valence of m. m+ represents m and M in the general formula (a01-b). m+ is the same as: Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or more.

[0460] Among the above, the cation portion of the (B) component is preferably a sulfonium cation, more preferably the cations represented by the above formulas (ca-1) to (ca-3), still more preferably the cation represented by the above formula (ca-1), and particularly preferably the cations represented by the above formulas (ca-1-1) to (ca-1-87).

[0461] In the resist composition, the component (B) may use either a single type, or a combination of two or more types. In the resist composition, the content of the component (B) per 100 parts by mass of the component (A1) is preferably less than 50 parts by mass, more preferably 0 to 40 parts by mass, even more preferably 0 to 30 parts by mass, and even more preferably 0 to 20 parts by mass. By setting the content of the component (B) within the above-mentioned preferred range, sufficient pattern formation can be achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0462] Base component (D) The resist composition to be filtered may further contain, in addition to the component (A), a base component (component (D)) that traps the acid generated upon exposure (i.e., controls the diffusion of the acid). The component (D) acts as a quencher (acid diffusion controller) that traps the acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure to light and loses its acid diffusion controllability, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred because it is easy to enhance all of the properties of high sensitivity, reduced roughness, and suppression of the occurrence of coating defects. The compounds exemplified as component (D1) described below may be used as the above-mentioned acid generator component (component (B)) depending on the combination with other compounds.

[0463] Regarding component (D1) By using a resist composition that contains the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) is not particularly limited as long as it decomposes upon exposure to light and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"): The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control ability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0464] [ka] [In the formula, Rd 1 ~Rd 4is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an organic cation having a valence of m.

[0465] {(d1-1) component} Anion part In formula (d1-1), Rd 1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, each of which is represented by the R' 201 The same can be mentioned. Among these, Rd 1 is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (y-al-1) to (y-al-5). Note that Rd 1 In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (d1-1) has a linking group represented by the above general formulas (y-al-1) to (y-al-7) as a substituent, in the above general formulas (y-al-1) to (y-al-7), Rd 1 The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the above formula (y-al-1) to (y-al-7) is bonded to V' 101 It is. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms. Specific examples of the chain alkyl group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0466] When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0467] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0468] [ka]

[0469] ··Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+Suitable organic cations include those similar to those represented by the general formulas (ca-1) to (ca-3) above, with the cation represented by the general formula (ca-1) above being more preferred, and the cations represented by the general formulas (ca-1-1) to (ca-1-87) above being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0470] {(d1-2) component} Anion part In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the R' 201 The same can be mentioned. However, Rd 2 In the above, the carbon atom adjacent to the S atom does not have a fluorine atom bonded thereto (is not substituted with fluorine), and this makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability of the (D) component. Rd 2 is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1 Examples of the substituent include the same as the substituents that may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0471] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0472] [ka]

[0473] ··Cation part In formula (d1-2), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0474] {Component (d1-3)} Anion part In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and R' 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 More preferred are the same fluorinated alkyl groups as those mentioned above.

[0475] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the R' 201 The same can be mentioned. Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Rd 4The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0476] Rd 4 The alkenyl group in R' 201 Examples of the alkenyl group include the same as the alkenyl group in the above, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0477] Rd 4 The cyclic group in R' 201 Examples of the cyclic groups include those similar to those in the above formula, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, and the lithography properties become good. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency and exhibits favorable sensitivity and lithography properties.

[0478] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. 21Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as mentioned in the description of the divalent linking group in the above. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0479] Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[0480] [ka]

[0481] [ka]

[0482] ··Cation part In formula (d1-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0483] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of the component (A1). When the amount of the component (D1) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0484] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing the component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0485] Regarding component (D2) The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above-mentioned component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under the category of component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0486] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0487] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0488] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, and the like.

[0489] The component (D2) may be used alone or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is usually within the range of 0.01 to 5 parts by mass relative to 100 parts by mass of the component (A1). By ensuring that the amount is within this range, the resist pattern shape and stability over time during storage can be improved.

[0490] At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof The resist composition to be filtered may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxoacids and derivatives thereof (hereinafter referred to as "component (E)") for the purposes of preventing deterioration in sensitivity and improving the resist pattern shape and stability over time during storage. Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, and among these, salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups. Examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid. In the resist composition, the component (E) may use either a single type, or a combination of two or more types. When the resist composition contains the component (E), the content of the component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the component (A1). By ensuring that the content is within the above range, the sensitivity and lithography properties, etc. are improved.

[0491] Fluorine additive component (F) The resist composition to be filtered may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film, and when used as a resin separate from component (A), it can improve lithography properties. As the component (F), for example, fluorine-containing polymeric compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, the component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1). The polymer may be a polymer (homopolymer) consisting of only the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), and more preferably a copolymer of the structural unit (f1) and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0492] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different. 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0493] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in R include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf 103 Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and further preferably a hydrogen atom. In formula (f1-1), nf 1 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0494] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched or cyclic and preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and particularly preferably has 1 to 10 carbon atoms. Furthermore, in the hydrocarbon group containing fluorine atoms, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more are fluorinated, as this enhances the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0495] The weight average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. When it is below the upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is above the lower limit of this range, the resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0496] In the resist composition, the component (F) may use either a single type, or a combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A1).

[0497] The resist composition to be filtered may further contain, if desired, compatible additives such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like.

[0498] According to the manufacturing method of the resist composition refined product of this embodiment described above, in step (i), the object to be filtered (resist composition) is filtered by a filter having a porous membrane having a porous structure in which adjacent spherical cells are connected to each other and containing at least one resin skeleton selected from the group consisting of polyimide and polyamideimide. This allows foreign matter such as organic matter and metal impurities to be removed from the object to be filtered more than ever before. In particular, by using a polyimide-based resin porous membrane, highly polar components and polymers that have been difficult to remove in the past are sufficiently removed from the object to be filtered, and among them, highly polar polymers are specifically removed. In addition, in step (i), metal components are also sufficiently removed as impurities from the object to be filtered. In this way, various foreign matters are efficiently removed by this manufacturing method, and a highly pure resist composition refined product is obtained. Furthermore, according to the method for producing a purified resist composition of this embodiment, in step (i), a resist composition containing the components (A1) and (S) is filtered. The component (A1) used contains a copolymer having a structural unit (a01) with an onium salt structure that generates sulfonic acid upon exposure, and a structural unit (a02) with an onium salt structure that generates carboxylic acid upon exposure. The onium salt structure moieties of the structural units (a01) and (a02) have relatively high polarity, and the copolymer having these structural units immediately after synthesis and the resist composition containing the same tend to contain a large amount of insoluble gelled matter derived from the highly polar component as an impurity. In this way, the method for producing a purified resist composition of the present embodiment employs a filter that is particularly suited to the object to be filtered, that is, "a resist composition that contains a specific copolymer having the structural units (a01) and (a02)", and therefore impurities are further reduced and the occurrence of defects during resist film formation can be sufficiently suppressed.

[0499] The filter in this embodiment is not limited to one having a porous membrane with communicating holes 5 connecting adjacent spherical cells 1a and 1b as shown in FIG. 1, but may have a porous membrane with cells or communicating holes of other shapes in addition to the communicating holes 5 connecting the spherical cells 1a and 1b. Cells of other shapes (hereinafter referred to as "other cells") include cells with different shapes or pore sizes, such as elliptical cells, polyhedral cells, spherical cells with different pore sizes, etc. The "communicating holes of other shapes" include, for example, communicating holes in which spherical cells communicate with other cells. The shape or pore size of the other cells may be appropriately determined depending on the type of impurities to be removed. The communicating holes that connect the spherical cells to the other cells can be formed by selecting the material of the above-mentioned fine particles or by controlling the shape of the fine particles. A filter having a porous membrane in which, in addition to the communicating holes connecting adjacent spherical cells, other types of cells or communicating holes are formed, can more efficiently remove various foreign matter from the material to be filtered.

[0500] In addition, the filter equipped with a polyimide-based resin porous membrane used in the filtration step can be used in place of or in combination with a filter cartridge or the like that has been installed in the supply line or POU (point of use) of the resist composition in the semiconductor manufacturing process for removing particulate impurities. Therefore, various foreign matters can be efficiently removed from the object to be filtered using the same equipment and operation as in the past, and a high-purity resist composition refined product can be produced.

[0501] (Method of forming a resist pattern) A method of forming a resist pattern according to a second aspect of the present invention includes the steps of obtaining a purified resist composition by the method of producing a purified resist composition according to the first aspect, forming a resist film on a support using the purified resist composition, exposing the resist film, and developing the exposed resist film to form a resist pattern. The resist pattern forming method of this embodiment can be carried out, for example, as follows.

[0502] First, a purified resist composition product is obtained by the method for producing a purified resist composition product according to the first aspect. Next, the purified resist composition is applied onto a support using a spinner or the like, and baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern is formed, or by lithography using direct irradiation with an electron beam without using a mask pattern. Thereafter, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0503] After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse liquid containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be carried out in which the developer or rinsing liquid adhering to the pattern is removed by using a supercritical fluid. After the development treatment or rinsing treatment, drying is performed. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

[0504] The support is not particularly limited, and may be a conventionally known support, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed. More specifically, it may be a silicon wafer, a substrate made of metal such as copper, chromium, iron, or aluminum, or a glass substrate. As the material for the wiring pattern, for example, copper, aluminum, nickel, or gold may be used.

[0505] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used. The method for forming a resist pattern of this embodiment is useful for exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0506] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure tool is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed, and examples of such a solvent include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent. As the liquid immersion medium, water is preferably used.

[0507] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving the component (A1) (the component (A1) before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0508] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0509] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0510] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0511] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it there for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0512] The organic solvent contained in the rinse solution used in the rinsing treatment after the development treatment in the solvent development process can be appropriately selected from the organic solvents listed above as the organic solvents used in the organic developer, which do not easily dissolve the resist pattern. Usually, at least one solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination of two or more thereof, and may be used in combination with other organic solvents or water.

[0513] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0514] According to the method of forming a resist pattern of the present aspect described above, a purified resist composition obtained by the production method of the first aspect is used, so the occurrence of defects is further suppressed and problems such as the occurrence of scum and microbridges are reduced, making it possible to form a resist pattern with a good shape.

[0515] The defect count for the resist pattern is determined by measuring the total number of defects (total number of defects, unit: pieces) in the support using a surface defect observation device (eg, manufactured by KLA Tencor Corporation).

[0516] (Refined resist composition products) The purified resist composition according to the third aspect of the present invention contains a resin component (A1) whose solubility in a developer changes under the action of an acid, and an organic solvent component. The resin component (A1) contains a copolymer having a structural unit (a01) having an onium salt structure that generates a sulfonic acid upon exposure, and a structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure. The purified resist composition product is characterized in that the number of counted particles having a size of 0.135 μm or more, as counted by a light scattering type liquid-borne particle counter, is 0.1 particles / mL or less.

[0517] The resist composition purified product according to this embodiment can be obtained by the manufacturing method of the resist composition purified product according to the first embodiment described above. The resist composition purified product obtained by the manufacturing method according to the first embodiment is filtered through a filter equipped with a polyimide resin porous membrane, thereby removing foreign matter. Therefore, in the resist composition purified product according to this embodiment, the number of counted objects having a size of 0.135 μm or more, as counted by a light scattering type liquid-borne particle counter, is 0.1 particles / mL or less, and a resist composition purified product with an extremely small number of foreign matter can be realized. Because such purified resist composition contains an extremely small number of foreign matter, a resist pattern with few defects can be formed. As the light scattering type liquid particle counter, for example, KS-41 manufactured by Rion Co., Ltd. can be used.

[0518] In the resist composition purified product according to this embodiment, the content of a metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is preferably less than 1.1 ppb, more preferably 1 ppb or less, more preferably 0.9 ppb or less, even more preferably 0.85 ppb or less, and particularly preferably 0.8 ppb or less.

[0519] The resist composition refined product according to this embodiment contains a resin component (A1) whose solubility in a developer changes under the action of an acid, and an organic solvent component, and the resin component (A1) contains a copolymer having a structural unit (a01) having an onium salt structure that generates a sulfonic acid upon exposure, and a structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure. The resist composition refined product is characterized in that the content of a metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is less than 1.1 ppb.

[0520] The resist composition refined product according to this embodiment can be obtained by the method for producing a resist composition refined product according to the first embodiment described above. The resist composition refined product obtained by the method for producing the resist composition refined product according to the first embodiment is filtered through a filter equipped with a polyimide resin porous membrane, thereby removing metal impurities. Therefore, in the resist composition refined product according to this embodiment, the content of a metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is less than 1.1 ppb, and a resist composition product with very few metal impurities can be realized.

[0521] The various base components, acid generators, acid diffusion controllers, organic solvents, and the like that are blended into the resist composition contain metal components such as trace amounts of metal ion impurities. These metal components may be originally contained in the blended components, but may also be mixed in through chemical solution transfer paths such as piping and joints in the manufacturing equipment, etc. The manufacturing method for a purified resist composition product according to the first aspect described above can effectively remove these metal components. In the purified resist composition according to this embodiment, the content of metal elements is preferably 1 ppb or less, more preferably 0.9 ppb or less, and even more preferably 0.85 ppb or less. Because the purified resist composition according to this embodiment has such an extremely low content of metal elements, a resist pattern with few defects can be formed.

[0522] The content of the metal elements is the total content of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb. The content of the metal elements in the purified resist composition product can be measured using an inductively coupled plasma mass spectrometer (ICP-MS 8900, manufactured by Agilent).

[0523] In a preferred embodiment, the purified resist composition product has a number of counted particles having a size of 0.135 μm or more, as counted by a light scattering type liquid particle counter, of 0.1 particles / mL or less, and has a content of a metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb of less than 1.1 ppb.

[0524] The purified resist composition according to the third aspect preferably has the same composition as the resist composition used in the method for producing a purified resist composition according to the first aspect described above, except that foreign matter and metal components have been removed.

[0525] The purified resist composition according to the third aspect can also be produced, for example, by a production method including the following steps (a) to (c). Step (a): A step of filtering a resin solution in which a resist resin component (component (A1)) is dissolved in an organic solvent component through a filter equipped with a polyimide-based resin porous membrane to obtain a purified resin solution. Step (b): A step of mixing the purified resin solution with other components (the above-mentioned component (B), component (D), component (E), component (F), or the like) to obtain a resist composition. Step (c): filtering the resist composition through a filter having a polyimide-based resin porous membrane.

[0526] (Method of forming a resist pattern) A method for forming a resist pattern according to a fourth aspect of the present invention includes the steps of forming a resist film on a support using the purified resist composition according to the third aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. The method for forming a resist pattern according to this embodiment can be carried out in the same manner as the method for forming a resist pattern according to the second embodiment described above. EXAMPLES

[0527] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0528] <Production of purified resist composition> (Examples 1 to 8, Co...

Claims

1. A method for producing a purified resist composition product, comprising: a step (i) of filtering a resist composition through a filter having a porous structure in which adjacent spherical cells are connected to each other, The filter includes a porous membrane containing at least one resin selected from the group consisting of polyimide and polyamideimide, The resist composition contains a resin component (A1) whose solubility in a developer changes under the action of an acid, and an organic solvent component; The resin component (A1) is a structural unit (a01) having an onium salt structure that generates sulfonic acid upon exposure to light; A structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure to light; The copolymer includes a copolymer having the formula: A method for producing a purified resist composition product.

2. 2. The method for producing a purified resist composition product according to claim 1, wherein the structural unit (a01) is a structural unit derived from a compound represented by the following general formula (a01-b): 【Chemistry 1】 [In formula (a01-b), W ０１ is a polymerizable group-containing group. ０１ R is a divalent linking group or a single bond. ０１ and R ０２ Each of M is independently a fluorinated alkyl group, a fluorine atom, or a hydrogen atom. ｍ＋ is an onium cation having a valence of m, where m is an integer of 1 or more.

3. 2. The method for producing a purified resist composition product according to claim 1, wherein the structural unit (a02) is a structural unit derived from a compound represented by the following general formula (a02-d): 【Chemistry 2】 [In formula (a02-d), W ０２ is a polymerizable group-containing group. ０２ is a divalent linking group or a single bond. ｎ＋ is an onium cation having a valence of n, where n is an integer of 1 or more.

4. 3. The method for producing a purified resist composition product according to claim 2, wherein the structural unit (a01) is a structural unit represented by the following general formula (a01-b0): 【Chemistry 3】 [In the formula, R ｍ represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. ０１ represents a divalent linking group or a single bond. ０１ represents a hydrocarbon group which may have a substituent. ０１ represents a divalent linking group or a single bond. ０１ represents a fluorinated alkylene group, an alkylene group, or a single bond. ０１ and Va ０１ are not both single bonds. ００ is a fluorinated alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a hydrogen atom. ｍ＋ is an onium cation having a valence of m, where m is an integer of 1 or more.

5. 4. The method for producing a purified resist composition product according to claim 3, wherein the structural unit (a02) is a structural unit represented by the following general formula (a02-d0): 【Chemistry 4】 [In the formula, R ｍ represents an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. ０２ represents a divalent linking group or a single bond. ０２ represents a hydrocarbon group which may have a substituent. ０２ represents a divalent linking group or a single bond. ｎ＋ is an onium cation having a valence of n, where n is an integer of 1 or more.

6. 2. The method for producing a purified resist composition product according to claim 1, wherein the resin component (A1) contains a copolymer having the structural unit (a01), the structural unit (a02), and a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid.

7. 2. The method for producing a purified resist composition product according to claim 1, wherein the average pore size of the spherical cells is 10 to 2500 nm.

8. 2. The method for producing a purified resist composition product according to claim 1, wherein the adjacent spherical cells communicate with each other to form interconnected pores, each of which has an average pore size of 1 to 1000 nm.

9. The method for producing a purified resist composition product according to claim 1 , wherein the filter comprises a polyimide-based resin porous membrane.

10. Prior to the step (i), 2. The method for producing a purified resist composition product according to claim 1, further comprising the step (ii) of cleaning said filter by contacting said filter with a membrane cleaning solution.

11. A step of obtaining a purified resist composition product by the method for producing a purified resist composition product according to any one of claims 1 to 10; forming a resist film on a support using the purified resist composition; exposing the resist film to light; developing the exposed resist film to form a resist pattern; The method for forming a resist pattern comprises the steps of:

12. A purified resist composition product comprising a resin component (A1) whose solubility in a developer changes under the action of an acid, and an organic solvent component, The resin component (A1) is a structural unit (a01) having an onium salt structure that generates sulfonic acid upon exposure to light; A structural unit (a02) having an onium salt structure that generates a carboxylic acid upon exposure to light; The copolymer comprises A purified resist composition product, in which the number of counted particles having a size of 0.135 μm or more, as counted by a light scattering type liquid particle counter, is 0.1 particles / mL or less.

13. forming a resist film on a support using the purified resist composition according to claim 12; exposing the resist film to light; developing the exposed resist film to form a resist pattern; The method for forming a resist pattern comprises the steps of:

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